Question

ok who can help me ill post the link to the problem just give me a second the first link will be the problem and the second link will be what has to be plugged in

Answer 1

i know f^-1 means inverse but I'm lost after that

Answer 2

how is f(x) defined?

Answer 3

or in this case, f(r) maybe?

Answer 4

f(r) is just that the problem is A=pir^2 i know we have to plug in the 4 into the problem but I'm lost after there

Answer 5

in general: of f and g are inverses then f(g(x)) = x

in other words, let A = 4, and solve for r

Answer 6

ok i understand that but i just can't seem to get a answer that makes sense

Answer 7

4 = pi (f'(4))^2

4/pi = (f'(4))^2

sqrt(4/pi) = f'(4)

Answer 8

or seen another similar way

f(r) = pi r^2

f(f'(4)) = pi [f'(4)]^2

4 = pi [f'(4)]^2

etc ....

Answer 9

ok so thats the answer 4= pi[f^(4)]^2

Answer 10

thats not the answer, that is the setup for how we can determine f'(4)

Answer 11

oh ok

Answer 12

in other words, what value of r makes:

4 = pi r^2 a true statement, solve for r

Answer 13

ok i still have no idea i understand sort of but i still don't understand how to get the answer from that