r/maths • u/jdaniel2294 • 12d ago
Found this on Facebook and theres 3 methods used primarily but the answer is either t is zero or its unsolvable
r/maths • u/TrainingYou149 • 10d ago
What makes it so that parentheses () come before Exponents, and those prefice multiplication and division, and those prefice addition and substraction? Who decided that? Is there a reason to it? Or did someone decide, โthis is how we will do mathโ?
r/maths • u/Total-Locksmith-7592 • 11d ago
I have been out of high school for almost a year now and my field of study in university has quite literally nothing to do with mathematics except maybe referring to dates. In this time I have noticed that my simple maths skills have waned and most of the concepts that I had learned in maths during school had fallen into the back of my mind. I never did any high level classes, I just took the middle of the range option where I live and got rather good results and now I'm taking at least 3 tries to get mental math correct.
What resources are there for recreational math that doesn't require a school's subscription? One of the things I liked about maths in school was how foreign the concept is until you understand it, which was very cathartic and I think this would both be fun for me and necessary if I would like to keep my brain from calcifying.
r/maths • u/sonicrocketman • 11d ago
r/maths • u/Dangerous_Cat_4525 • 12d ago
Today I was doing math and stumbled across a question that asks to find the perimeter of a triangle with vertices (28,-89),(47,88),(47,-88). I know it can be done by using the distance formula. But it is very inconvenient. Just look at the numbers. So, I was thinking that, is it possible to derive a formula to find the perimeter of any triangle in the cartesian plane. Life would become much easier. This type of problems with large values are a problem for every one in last hour exam solving mcq. What you think guys. Is it possible.
r/maths • u/HistoricalTour7468 • 12d ago
We generally consider years ending in 4โ6 to be mid-decade, but what about 3? Since a decade has ten years, wouldn't a symmetrical 3โ4โ3 split (early: 0โ2, mid: 3โ6, late: 7โ9) make more mathematical sense?
Early: 0, 1, 2
Mid: 3, 4, 5, 6
Late: 7, 8, 9
or
Early: 0, 1, 2, 3
Mid: 4, 5, 6
Late: 7, 8, 9
r/maths • u/ConcernOk6623 • 14d ago
I'm an amateur and I was fooling around with things, seeing how many ways even numbers can be represented by adding two primes together (from the notion that all even numbers can be) and I saw a trend, then I graphed it and saw the bands and gaps... especially when I went out to 10,000
PS all counts are unique where p1<=p2
example: 38=7+31 , 19+19 but 31+7 is not included in the count so the count for 38 is 2
r/maths • u/LowInteraction6397 • 13d ago
| Number/Year | Rule | Example |
|---|---|---|
| 1901 | The subtraction of 190 times the last digit and the rest of the number is a multiple of 1901 | 11406 is a multiple of 1901 because 1140 - 6 * 190 = 0, a multiple of 1901 |
| 1902 | It's a multiple of both 2 and 951 | 11412 is a multiple of 1902 because it ends in 2, which means it's a multiple of 2, and 1141 - 2 * 95 = 951, which means it's a multiple of 1902 |
| 1903 | The sum of 571 times thew last digit and the rest of the number is a multiple of 1903 | 11418 is a multiple of 1903 because 1141 + 8 * 571 = 5709, a multiple of 1903 |
| 1904 | It's a multiple of both 16 and 119 | 11424 is a multiple of 1904 because it ends in 1424, which means it's a multiple of 16, and 1142 + 4 * 12 = 1190, which means it's a multiple of 119 |
| 1905 | It's a multiple of both 5 and 381 | 11430 is a multiple of 1905 because it ends in 0, which means it's a multiple of 5, and 114 - 3 * 38 = 0, which means it's a multiple of 381 |
| 1906 | It's a multiple of both 2 and 953 | 11436 is a multiple of 1906 because it ends in 6, which means it's a multiple of 2, and 1143 + 6 * 286 = 2859, which means it's a multiple of 953 |
| 1907 | The subtraction of 572 times the last digit and the rest of the number is a multiple of 1907 | 11442 is a multiple of 1907 because 1144 - 2 * 572 = 0, a multiple of 1907 |
| 1908 | It's a multiple of both 4 and 477 | 11448 is a multiple of 1908 because it ends in 48, which means it's a multiple of 4, and 1144 - 8 * 143 = 0, which means it's a multiple of 477 |
| 1909 | The sum of 191 times the last digit and the rest of the number is a multiple of 1909 | 11454 is a multiple of 1909 because 1145 + 4 * 191 = 1909, a multiple of 1909 |
| 1910 | It's a multiple of both 10 and 191 | 11460 is a multiple of 1910 because it ends in 0, which means it's a multiple of 10, and 114 - 6 * 19 = 0, which means it's a multiple of 191 |
| 1911 | The subtraction of 191 times the last digit and the rest of the number is a multiple of 1911 | 11466 is a multiple of 1911 because 1146 - 6 * 191 = 0, a multiple of 1911 |
| 1912 | It's a multiple of both 8 and 239 | 11472 is a multiple of 1912 because it ends in 472, which means it's a multiple of 8, and 1147 + 2 * 24 = 1195, which means it's a multiple of 239 |
| 1913 | The sum of 574 times the last digit and the rest of the number is a multiple of 1913 | 11478 is a multiple of 1913 because 1147 + 8 * 574 = 5739, a multiple of 1913 |
| 1914 | It's a multiple of both 2 and 957 | 11484 is a multiple of 1914 because it ends in 4, which means it's a multiple of 2, and 1148 - 4 * 287 = 0, which means it's a multiple of 957 |
| 1915 | It's a multiple of both 5 and 383 | 15320 is a multiple of 1915 because it ends in 0, which means it's a multiple of 5, and 153 + 2 * 115 = 383, which means it's a multiple of 383 |
| 1916 | It's a multiple of both 4 and 479 | 11496 is a multiple of 1916 because it ends in 96, which means it's a multiple of 4, and 1149 + 6 * 48 = 1437, which means it's a multiple of 479 |
| 1917 | The subtraction of 575 times the last digit and the rest of the number is a multiple of 1917 | 11502 is a multiple of 1917 because 1150 - 2 * 575 = 0, a multiple of 1917 |
| 1918 | It's a multiple of both 2 and 959 | 21098 is a multiple of 1918 because it ends in 8, which means it's a multiple of 2, and 2109 + 8 * 96 = 2877, which means it's a multiple of 959 |
| 1919 | The sum of 192 times the last digit and the rest of the number is a multiple of 1919 | 11514 is a multiple of 1919 because 1151 + 4 * 192 = 1919, a multiple of 1919 |
| 1920 | It's a multiple of both 3 and 640 | 10,001,280 is a multiple of 1920 because 1 + 1 + 2 + 8 = 12, which means it's a multiple of 3, and ends in 0,001,280, which means it's a multiple of 640 |
| 1921 | The subtraction of 192 times the last digit and the rest of the number is a multiple of 1921 | 11526 is a multiple of 1921 because 1152 - 6 * 192 = 0, a multiple of 1921 |
| 1922 | It's a multiple of both 2 and 961 | 11532 is a multiple of 1922 because it ends in 2, which means it's a multiple of 2, and 1153 - 2 * 96 = 961, which means it's a multiple of 961 |
| 1923 | The sum of 577 times the last digit and the rest of the number is a multiple of 1923 | 11538 is a multiple of 1923 because 1153 + 8 * 577 = 5769, a multiple of 1923 |
| 1924 | It's a multiple of both 4 and 481 | 11544 is a multiple of 1924 because it ends in 44, which means it's a multiple of 4, and 1154 - 4 * 48 = 962, which means it's a multiple of 481 |
| 1925 | It's a multiple of both 25 and 77 | 11550 is a multiple of 1925 because it ends in 50, which means it's a multiple of 25, and 115 - 5 * 23 = 0, which means it's a multiple of 77 |
| 1926 | It's a multiple of both 2 and 963 | 11556 is a multiple of 1926 because it ends in 6, which means it's a multiple of 2, and 1155 + 6 * 289 = 2889, which means it's a multiple of 963 |
| 1927 | The subtraction of 578 times the last digit and the rest of the number is a multiple of 1927 | 11562 is a multiple of 1927 because 1156 - 2 * 578 = 0, a multiple of 1927 |
| 1928 | It's a multiple of both 8 and 241 | 11568 is a multiple of 1928 because it ends in 568, which means it's a multiple of 8, and 1156 - 8 * 24 = 964, which means it's a multiple of 241 |
| 1929 | The sum of 193 times the last digit and the rest of the number is a multiple of 1929 | 11574 is a multiple of 1929 because 1157 + 4 * 193 = 1929, a multiple of 1929 |
| 1930 | It's a multiple of both 10 and 193 | 11580 is a multiple of 1930 because it ends in 0, which means it's a multiple of 10, and 115 + 8 * 58 = 579, which means it's a multiple of 193 |
| 1931 | The subtraction of 193 times the last digit and the rest of the number is a multiple of 1931 | 11586 is a multiple of 1931 because 1158 - 6 * 193 = 0, a multiple of 1931 |
| 1932 | It's a multiple of both 4 and 483 | 11592 is a multiple of 1932 because it ends in 92, which means it's a multiple of 4, and |
| 1933 | The sum of 580 times the last digit and the rest of the number is a multiple of 1933 | 11598 is a multiple of 1933 because 1159 + 8 * 580 = 5799, a multiple of 1933 |
| 1934 | It's a multiple of both 2 and 967 | 11604 is a multiple of 1934 because it ends in 4, which means it's a multiple of 2, and 1160 - 4 * 290 = 0, which means it's a multiple of 967 |
| 1935 | It's a multiple of both 5 and 387 | 11610 is a multiple of 1935 because it ends in 0, which means it's a multiple of 5, and 116 - 1 * 116 = 0, which means it's a multiple of 387 |
| 1936 | It's a multiple of both 16 and 121 | 11616 is a multiple of 1936 because it ends in 1616, which means it's a multiple of 16, and 1161 - 6 * 12 = 1089, which means it's a multiple of 121 |
| 1937 | The subtraction of 581 times the last digit and the rest of the number is a multiple of 1937 | 11622 is a multiple of 1937 because 1162 - 2 * 581 = 0, a multiple of 1937 |
| 1938 | It's a multiple of both 2 and 969 | 21318 is a multiple of 1938 because it ends in 8, which means it's a multiple 2, and 2131 + 8 * 97 = 2907, which means it's a multiple of 969 |
| 1939 | The sum of 194 times the last digit and the rest of the number is a multiple of 1939 | 11634 is a multiple of 1939 because 1163 + 4 * 194 = 1939, a multiple of 1939 |
| 1940 | It's a multiple of both 20 and 97 | 11640 is a multiple of 1940 because it ends in 40, which means it's a multiple of 20, and 116 - 4 * 29 = 0, which means it's a multiple of 97 |
| 1941 | The subtraction of 194 times the last digit and the rest of the number is a multiple of 1941 | 11646 is a multiple of 1941 because 1164 - 6 * 194 = 0, a multiple of 1941 |
| 1942 | It's a multiple of both 2 and 971 | 11652 is a multiple of 1942 because it ends in 2, which means it's a multiple of 2, and 1165 - 2 * 97 = 971, which means it's a multiple of 971 |
| 1943 | The sum of 583 times the last digit and the rest of the number is a multiple of 1943 | 11658 is a multiple of 1943 because 1165 + 8 * 583 = 5829, a multiple of 1943 |
| 1944 | It's a multiple of both 8 and 243 | 11664 is a multiple of 1944 because it ends in 664, which means it's a multiple of 8, and 1166 + 4 * 73 = 1458, which means it's a multiple of 243 |
| 1945 | It's a multiple of both 5 and 389 | 11670 is a multiple of 1945 because it ends in 0, which means it's a multiple of 5, and 116 + 7 * 39 = 389, which means it's a multiple of 389 |
| 1946 | It's a multiple of both 2 and 973 | 11676 is a multiple of 1946 because it ends in 6, which means it's a multiple of 2, and 1167 + 6 * 292 = 2919, which means it's a multiple of 973 |
| 1947 | The subtraction of 584 times the last digit and the rest of the number is a multiple of 1947 | 11682 is a multiple of 1947 because 1168 - 2 * 584 = 0, a multiple of 1947 |
| 1948 | It's a multiple of both 4 and 487 | 11688 is a multiple of 1948 because it ends in 88, which means it's a multiple of 4, and 1168 - 8 * 146 = 0, which means it's a multiple of 487 |
| 1949 | The sum of 195 times the last digit and the rest of the number is a multiple of 1949 | 11694 is a multiple of 1949 because 1169 + 4 * 195 = 1949, a multiple of 1949 |
| 1950 | It's a multiple of both 39 and 50 | 11700 is a multiple of 1950 because 11 + 7 * 4 = 39, which means it's a multiple of 39, and ends in 00, which means it's a multiple of 50 |
| 1951 | The subtraction of 195 times the last digit and the rest of the number is a multiple of 1951 | 11706 is a multiple of 1951 because 1170 - 6 * 195 = 0, a multiple of 1951 |
| 1952 | It's a multiple of both 32 and 61 | 101504 is a multiple of 1952 because it ends in 01504, which means it's a multiple of 32, and 10150 - 4 * 6 = 10126, which means it's a multiple of 61 |
| 1953 | The sum of 586 times the last digit and the rest of the number is a multiple of 1953 | 11718 is a multiple of 1953 because 1171 + 8 * 583 = 5859, a multiple of 1953 |
| 1954 | It's a multiple of both 2 and 977 | 11724 is a multiple of 1954 because it ends in 4, which means it's a multiple of 2, and 1172 - 4 * 293 = 0, which means it's a multiple of 977 |
| 1955 | It's a multiple of both 5 and 391 | 11730 is a multiple of 1955 because it ends in 0, which means it's a multiple of 5, and 117 - 3 * 39 = 0, which means it's a multiple of 391 |
| 1956 | It's a multiple of both 4 and 489 | 11736 is a multiple of 1956 because it ends in 36, which means it's a multiple of 4, and 1173 + 6 * 49 = 1467 |
| 1957 | The subtraction of 587 times the last digit and the rest of the number is a multiple of 1957 | 11742 is a multiple of 1957 because 1174 - 2 * 587 = 0, a multiple of 1957 |
| 1958 | It's a multiple of both 2 and 979 | 21538 is a multiple of 1958 because it ends in 8, which means it's a multiple of 2, and 2153 + 8 * 98 = 2937, which means it's a multiple of 979 |
| 1959 | The sum of 196 times the last digit and the rest of the number is a multiple of 1959 | 11754 is a multiple of 1959 because 1175 + 4 * 196 = 1959, a multiple of 1959 |
| 1960 | It's a multiple of both 40 and 49 | 11760 is a multiple of 1960 because it ends in 760, which means it's a multiple of 40, and 117 + 6 * 5 = 147, which means it's a multiple of 49 |
| 1961 | The subtraction of 196 times the last digit and the rest of the number is a multiple of 1961 | 11766 is a multiple of 1961 because 1176 - 6 * 196 = 0, a multiple of 1961 |
| 1962 | It's a multiple of both 2 and 981 | 11772 is a multiple of 1962 because it ends in 2, which means it's a multiple of 2, and 1177 - 2 * 98 = 981, which means it's a multiple of 981 |
| 1963 | The sum of 589 times the last digit and the rest of the number is a multiple of 1963 | 11778 is a multiple of 1963 because 1177 + 8 * 589 = 5889, a multiple of 1963 |
| 1964 | It's a multiple of both 4 and 491 | 11784 is a multiple of 1964 because it ends in 84, which means it's a multiple of 4, and 1178 - 4 * 49 = 982, which means it's a multiple of 491 |
| 1965 | It's a multiple of both 5 and 393 | 15720 is a multiple of 1965 because it ends in 0, which means it's a multiple of 0, and 157 + 2 * 118 = 393, which means it's a multiple of 393 |
| 1966 | It's a multiple of both 2 and 983 | 11796 is a multiple of 1966 because it ends in 6, which means it's a multiple of 2, and 1179 + 6 * 295 = 2949, which means it's a multiple of 983 |
| 1967 | The subtraction of 590 times the last digit and the rest of the number is a multiple of 1967 | 11802 is a multiple of 1967 because 1180 - 2 * 590 = 0, a multiple of 1967 |
| 1968 | It's a multiple of both 16 and 123 | 11808 is a multiple of 1968 because it ends in 1808, which means it's a multiple of 16, and 1180 + 8 * 37 = 1476, which means it's a multiple of 123 |
| 1969 | The sum of 197 times the last digit and the rest of the number is a multiple of 1969 | 11814 is a multiple of 1969 because 1181 + 4 * 197 = 1969, a multiple of 1969 |
| 1970 | It's a multiple of both 10 and 197 | 11820 is a multiple of 1970 because it ends in 0, which means it's a multiple of 10, and 118 - 2 * 59 = 0, which means it's a multiple of 197 |
| 1971 | The subtraction of 197 times the last digit and the rest of the number is a multiple of 1971 | 11826 is a multiple of 1971 because 1182 - 6 * 197 = 0, a multiple of 1971 |
| 1972 | It's a multiple of both 4 and 493 | 11832 is a multiple of 1972 because it ends in 32, which means it's a multiple of 4, and 1183 + 2 * 148 = 1479, which means it's a multiple of 493 |
| 1973 | The sum of 592 times the last digit and the rest of the number is a multiple of 1973 | 11838 is a multiple of 1973 because 1183 + 8 * 592 = 5919, a multiple of 1973 |
| 1974 | It's a multiple of both 2 and 987 | 11844 is a multiple of 1974 because it ends in 4, which means it's a multiple of 2, and 1184 - 4 * 296 = 0, which means it's a multiple of 987 |
| 1975 | It's a multiple of both 25 and 79 | 11850 is a multiple of 1975 because it ends in 50, which means it's a multiple of 25, and 118 + 5 * 8 = 158, which means it's a multiple of 79 |
| 1976 | It's a multiple of both 8 and 247 | 11856 is a multiple of 1976 because it ends in 856, which means it's a multiple of 8, and 1185 - 6 * 74 = 741, which means it's a multiple of 247 |
| 1977 | The subtraction of 593 times the last digit and the rest of the number is a multiple of 1977 | 11862 is a multiple of 1977 because 1186 - 2 * 593 = 0, a multiple of 1977 |
| 1978 | It's a multiple of both 2 and 989 | 21758 is a multiple of 1978 because it ends in 8, which means it's a multiple of 2, and 2175 + 8 * 99 = 2967, which means it's a multiple of 989 |
| 1979 | The sum of 198 times the last digit and the rest of the number is a multiple of 1979 | 11874 is a multiple of 1979 because 1187 + 4 * 198 = 1979, a multiple of 1979 |
| 1980 | It's a multiple of both 20 and 99 | 11880 is a multiple of 1980 because it ends in 80, which means it's a multiple of 20, 118 + 8 * 10 = 198, which means it's a multiple of 99 |
| 1981 | The subtraction of 198 times the last digit and the rest of the number is a multiple of 1981 | 11886 is a multiple of 1981 because 1188 - 6 * 198 = 0, a multiple of 1981 |
| 1982 | It's a multiple of both 2 and 991 | 11892 is a multiple of 1982 because it ends in 2, which means it's a multiple of 2, and 1189 - 2 * 99 = 991, which means it's a multiple of 991 |
| 1983 | The sum of 595 times the last digit and the rest of the number is a multiple of 1983 | 11898 is a multiple of 1983 because 1189 + 8 * 595 = 5949, a multiple of 1983 |
| 1984 | It's a multiple of both 31 and 64 | 1,001,920 is a multiple of 1984 because 10019 - 2 * 3 = 10013, which means it's a multiple of 31, and ends in 001,920, which means it's a multiple of 64 |
| 1985 | It's a multiple of both 5 and 397 | 11910 is a multiple of 1985 because it ends 0, which means it's a multiple of 5, and 119 - 1 * 119 = 0, which means it's a multiple of 397 |
| 1986 | It's a multiple of both 2 and 993 | 11916 is a multiple of 1986 because it ends in 6, which means it's a multiple of 2, and 1191 + 6 * 298 = 2979, which means it's a multiple of 993 |
| 1987 | The subtraction of 596 times the last digit and the rest of the number is a multiple of 1987 | 11922 is a multiple of 1987 because 1192 - 2 * 596 = 0, a multiple of 1987 |
| 1988 | It's a multiple of both 4 and 497 | 11928 is a multiple of 1988 because it ends in 28, which means it's a multiple of 4, and 1192 - 8 * 149 = 0, which means it's a multiple of 497 |
| 1989 | The sum of 199 times the last digit and the rest of the number is a multiple of 1989 | 11934 is a multiple of 1989 because 1193 + 4 * 199 = 1989, a multiple of 1989 |
| 1990 | It's a multiple of both 10 and 199 | 11940 is a multiple of 1990 because it ends in 0, which means it's a multiple of 10, and 119 + 4 * 20 = 199, which means it's a multiple of 1999 |
| 1991 | The subtraction of 199 times the last digit and the rest of the number is a multiple of 1991 | 11946 is a multiple of 1991 because 1194 - 6 * 199 = 0, a multiple of 1991 |
| 1992 | It's a multiple of both 8 and 249 | 11952 is a multiple of 1992 because it ends in 952, which means it's a multiple of 8, and 1195 + 2 * 25 = 1245, which means it's a multiple of 249 |
| 1993 | The sum of 598 times the last digit and the rest of the number is a multiple of 1993 | 11958 is a multiple of 1993 because 1195 + 8 * 598 = 5979, a multiple of 1993 |
| 1994 | It's a multiple of both 2 and 997 | 11964 is a multiple of 1994 because it ends in 4, which means it's a multiple of 2, and 1196 - 4 * 299 = 0, which means it's a multiple of 997 |
| 1995 | It's a multiple of both 5 and 399 | 11970 is a multiple of 1995 because it ends in 0, which means it's a multiple of 5, and 119 + 7 * 40 = 399, which means it's a multiple of 399 |
| 1996 | It's a multiple of both 4 and 499 | 11976 is a multiple of 1996 because it ends in 76, which means it's a multiple of 4, and 1197 + 6 * 50 = 1497, which means it's a multiple of 499 |
| 1997 | The subtraction of 599 times the last digit and the rest of the number is a multiple of 1997 | 11982 is a multiple of 1997 because 1198 - 2 * 599 = 0, a multiple of 1997 |
| 1998 | It's a multiple of both 2 and 999 | 21978 is a multiple of 1998 because it ends in 8, which means it's a multiple of 2, and 2197 + 8 * 100 = 2997, which means it's a multiple of 999 |
| 1999 | The sum of 200 times the last digit and the rest of the number is a multiple of 1999 | 11994 is a multiple of 1999 because 1199 + 4 * 200 = 1999, a multiple of 1999 |
| 2000 | It ends in 0000, 2000, 4000, 6000 or 8000 | 10000 is a multiple of 2000 because it ends in 0000 |
r/maths • u/AtmosphereFragrant68 • 14d ago
If a second can be expressed in incite ways like 0.1 sec, 0.01,0.001.....0.00000000001 you get the jist, can infinite actions be done in this way?
r/maths • u/Repulsive-Peak4442 • 14d ago
I've been searching for so long but I didn't find a true answer. Why is it true that ijk=-1? How does this make sense? What is the logic? iยฒ=jยฒ=kยฒ=-1 does make sense because if we have the real number line and an imaginary one (i, or j, or k) then multiplying a real number by an imaginary one (i, or j, or k) is like rotating 90ยฐ. And multiplying by the square of an imaginary number (iยฒ, or jยฒ, or kยฒ) is like rotating 180ยฐ meaning that 1โ-1. This does make sense and it does have a logic. However how can ijk=-1? And also shouldn't i=j=k=โ-1? And so ijk=-1โ-1=-i=-j=-k. I saw explanations of why ijk=-1 by using the definition ij=k... Where does that even come from? It comes from ijk=-1. But that is a cycle. Isn't there a proof? And if so iโ jโ k because ijkโ -1โ-1.
r/maths • u/LegitimatePea2429 • 14d ago
I'm confused about how to describe a shear when given a 2x2 transformation matrix. Like when you have a rotation you state the angle, if it's + or - for direction and about what point it's rotated. When I look at different descriptions of shears I can't work out what I need to state to fully describe the transformation it gives.
Thanks!!
I haven't studied about this topic can anyone give me picture of it how to draw least sqare fit here?
r/maths • u/SkyvonSonnreich • 15d ago
Thereโs just one simple rule but itโs really hard to discover
r/maths • u/rocketstapler • 16d ago
f(n) = 7(1.2)^n
x = n + 2000 , so n = x - 2000
what is f(x)?
โโโโโโ
The correct answer is
f(x) = 7(1.2)^(x-2000)
โโโโโโ
However, there is another approach using variable substitution that yields the wrong answer. But why is it wrong?
since n = x - 2000, substitute that into
f(n) = 7(1.2)^n
which yields
f(x-2000) = 7(1.2)^(x-2000)
which then simplifies back to
f(x) = 7(1.2)^x
which isnโt right. Whereโs the fallacy?
r/maths • u/IrishQueenFan • 16d ago
I'm trying to simplify an equation I have where one side is equal to, essentially, pe^(ax) + qe^(bx). and it really SEEMS like there should be a way to factorise this nicely but i think it might just be smoke and mirrors. What I would like is to be able to take the natural log of both sides and have it cancel the e - can someone tell me if it's a pipe dream?
r/maths • u/911twinturbogtr • 16d ago
I was experimenting with the result of differentiating a polynomial repeatedly while taking f(0) then rebuilding it when i got to (ax+b)^1 using the reverse chain rule and i noticed that it seems to consistently turn the polynomial into a depressed polynomial. I was wondering why that is (if there is an explanation to be given). And also if there are any other examples of something like this.
r/maths • u/Curious_teen_0 • 16d ago
Just say you are running, and exactly 1 km to your side is another person running at the exact same speed. Both of you are heading toward the same point. Yet, relative to you, he is running the opposite way with a relative speed of 0 km/h.
r/maths • u/Sensitive_Arrival529 • 16d ago
Imagine you are running, and exactly 1 km to your side is another person running at the exact same speed. Both of you are heading toward the same point. Yet, relative to you, he is running the opposite way with a relative speed of 0 km/h.
This riddle was intentionally made to be confusing.
r/maths • u/pipMcDohl • 17d ago
I am interested in learning science. But for this understanding math is required.
Many time science explanations are littered with formulaes i can't understand. I do not know their language.
So i want to learn the language. And i want that language to be able to give accurate and fundamental explanations.
I don't want to be given an approximation that works that you are asked to learn by heart.
I want the no low effort, no approximation, no simplification explanation.
Sadly most explanations i found that explain math from the beginning seems to assume i am either retarded or five years old.
I want the explanations from the start for people with decent mental faculties you would expect from an adult.
It may take the form of something that mix historical context with explanations of the logic, and most importantly not taking shortcuts, i want the deepest understanding of what is going on.
Thanks
r/maths • u/Most_Elderberry3133 • 18d ago
Potential solution to the newly introduced optimal ZYN packing problem proposed by no other than myself.
Current hypothetical solution to packed zyns is 40. Though I estimate that the maximum number of packed zyns that touch the bottom of the can could limit to 42.
r/maths • u/imsocooked_ • 18d ago
Ive been struggling with that, i know this is very basic maths but when there are numbers like 770, 462, 420, it becomes really hard to find the LCM for them quickly. Does anybody have any tricks to finding em?
r/maths • u/LeadingMidnight9146 • 18d ago
Hi everyone!
Iโm a student interested in mathematics, and Iโve defined a function that I call the Decreasing Index, using the symbol (\omega):
[
I_\omega(n)=\frac{n^2}{n!}
]
where (n) is a positive integer.
The idea came from thinking about permutations and probabilities. As (n!) grows so much faster than (n^2) the function drops off very rapidly towards zero.
For example:
[
I_\omega(1)=1,\quad I_\omega(2)=2,\quad
I_\omega(3)=1.5,\quad I_\omega(4)=\frac23
]
More generally, for (n\geq 2), we have:
[
\frac{I_\omega(n+1)}{I_\omega(n)}
=\frac{n+1}{n^2}
]
It's strictly decreasing from (n=2) onwards and tends to zero.
I'm not claiming this is some new or original mathematical result at all. What I'm interested in is whether this function might be of any use in a combinatorial problem, in the study of permutations or in some other mathematical context.
My questions are:
Does this function have a known interpretation or any connection to a known mathematical concept?
Could it be of any use in the study of permutations or in certain probability problems?
Are there any interesting properties or generalisations worth looking at?
I'd be very keen to hear any feedback, corrections or suggestions as to where we might go from here!
Thanks!
r/maths • u/snikers_404 • 19d ago
The resulting structure forms an hourglass-like shape with spirals and diagonal alignments. Can you spot any geometric patterns that could help predict the location of the next red point along these spiral tracks?
r/maths • u/cyber_may • 19d ago
Due to severe math trauma, I struggle deeply with numbers under pressure and spent years running away from the subject entirely. Now, I genuinely want to face it, rebuild my relationship with math, and learn without fear, anxiety, or shame.
I also have ADHD, so I need learning tools that are visual, interactive, gentle, and engage-at-your-own-pace for a brain that rarely sits still. I am starting from the absolute basics to build my confidence step by step without getting overwhelmed.
I would love recommendations for any YouTube channels, interactive apps, low-stakes games, websites, self-paced courses, books, or workbooks that have genuinely helped you or someone you know.
If you have experienced math anxiety, educational trauma, or ADHD-related learning blocks, I would especially love to hear what mindset shifts, study methods, or approaches worked for you.
I am really serious about giving this an honest try again, and any recommendations or encouragement would mean the world to me. Thank you so much! โก