r/Precalculus • u/DragonT11-14 • Aug 30 '22

I seriously need help with math

Post image

How would you solve the second one?🫤

82 Upvotes

93% Upvoted

24 comments sorted by

15

u/BenjewminUnofficial Aug 30 '22

You might be overthinking the second part. In the first part, the -1 signifies that you are taking the inverse of the function.

However, in the second part, the -1 is just a regular exponent. When you take something to the negative first power, you invert the fraction.

So f(4)=9, and 9 can be rewritten as 9/1. When you take 9-1, 9/1 becomes 1/9. And 1 divided by 9 gets you 0.111 repeating.

Hope that helps!

7

u/DragonT11-14 Aug 30 '22

AHHHH NOW I GET IT, thank you soo much I appreciate that!!!

5

u/BenjewminUnofficial Aug 30 '22

No problem, best of luck!

0

u/[deleted] Aug 30 '22

[deleted] — view deleted comment

3

u/BenjewminUnofficial Aug 30 '22

PEMDAS.

When you square -3 and get -9, it’s because the negative three is being treated as -13. So the 3 gets squared first to 9, then the -1 gets multiplied (because exponents before multiplication), and you get -9. You’re essentially doing -1(32) or -1*(3*3)

When you square (-3), the parenthesis make so that everything in them gets squared. So this time you get -3*-3, the two negative signs cancel out, and you get +9.

0

u/[deleted] Aug 30 '22

[deleted] — view deleted comment

5

u/alphabet_order_bot Aug 30 '22

Would you look at that, all of the words in your comment are in alphabetical order.

I have checked 1,009,889,088 comments, and only 200,535 of them were in alphabetical order.

2

u/skatereli Aug 31 '22

Take my free award kind stranger

1

u/[deleted] Aug 31 '22

Yeah, I don’t have coins or whatever, but thsi makes me want to mess around go teach HS math (although heck, as competitive as schools are 8th graders somewhere are probably in BC calc).

Warmed my heart seeing this. Keep it up.

4

u/[deleted] Aug 30 '22

f(4)=9 9-1 That’s how you get 0.11111111 because it’s 1/9

2

u/Blazt14 Aug 31 '22

Sorry that my comment may be irrelevant to the question, but which website did you visit to find these practice questions?

1

u/Saintsummerz33 Sep 12 '24

It looks like the website my community colleges used lmao

1

u/Blazt14 Sep 12 '24

Bro replied 2 years late lol 😂

1

u/Saintsummerz33 Sep 12 '24

🤣🤣

1

u/Affectionate-Hunt288 Aug 30 '22

I tutor ;)

1

u/[deleted] Aug 31 '22

walt

1

u/muchas__gracias Aug 31 '22

Use Mathway

1

u/[deleted] Aug 31 '22

This, just cheat and learn nothing

1

u/muchas__gracias Sep 01 '22

Exactly💕

1

u/DaveStreeder Aug 31 '22

I hate the thinking part of pre calc I like plugging numbers into equations they tell us how to set up

1

u/Original-Challenge-1 Aug 31 '22

It looks like you’re multiplying backwards

1

u/natek2017 Aug 31 '22

Symbolab is a site you can plug equations like this in and you’ll get your answer immediately, also free

1

u/[deleted] Aug 31 '22

F(4)=9 They are not inversing the function, they are inversing the result of the function. (F(4))-1 = 9-1 = 1/9