Question

Given the function f(x) = log4(x + 8), find the value of f−1(2).

a. f−1(2) = 4
b. f−1(2) = 8
c. f−1(2) = 10
d. f−1(2) = 17

Answer 1

hi are you still on? i can help

Answer 2

we need to find the inverse. do you know how to do that?

Answer 3

don't i replace x with y and y with x?

Answer 4

f(x) = log4(x + 8)
y = log4(x + 8)
x = log4(y + 8)

Now solve for y from there.
x = log4(y + 8)
\[f-1(x) = -8 + 4^x\]

Answer 5

now just plug in 2, what do you get?

Answer 6

-8 + 4^2
4^2 = 16
-8+16 = 8
your answer will be B.

Answer 7

do you need anymore help?

Answer 8

if so close this question and post another one and invite me. please medal me though

Answer 9

oh okay, thank you so so much! and yes, i do. is it okay if i post it separately? so incase any one else needs help, they can find it easier.

Answer 10

yes awesome