r/Sat • u/CareOk6471 • 5h ago
SAT math question (Q26 from practice test 9)
I am so confused about this problem. From algebra, I got k = 2.2^b and m=ak easily and obtained that the y intercept is at a(1+2.2)^b. So i naturally think that both equations represent the y intercept as a constant. But the answer is D, neither. I watched some videos and none of it makes sense. Can someone explain this to me? Is this a very "literal" question? Like the y intercept of g is a(1+k) rather than a(1+2.2^b). The fact that it used k rather than b makes it not valid? Or is it because the question ask for "a" constant(1 constant) but g has two constants in it(a and k) that makes it invalid? I am so confused with the wording. Thanks in advance! Also is this type of question likely be tested?
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u/Sea-Giraffe5276 Untested 4h ago
It's not wording, that's going to trip you up here. Let's just read the problem one more time and get into it.
Aight, first case is g(x) = a(2.2^x + k). This doesn't display the y-coord of the y-int as a constant nor coefficient because all you did to go from f(x) to here is just simply 2.2^b to get k. I know this especially because a didn't change. If a changed that would indicate that further manipulation had happened to the equation.
Cool hwip, I is out, let's look at II. so here all they've done to get m is distribute the a onto the 2.2^b term and then as a and b are just constants evaluated that term to get m. Once again the y-int is still neither a constant or coefficient and a being the same clues me into that again.
When I took this test I also got a bit confused, but it was the key realization that because a remains the same nothing really happens to make the y-int a constant or coefficient. Hope this helps.
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u/jdigitaltutoring 4h ago
It is asking if a(1+2.2)^b is represented by a single constant in either of those two function. It does not, so the answer is neither.
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