Question

If f(x) = log2(x+4), what is f-1(3)

Answer 1

Imma just solve for f⁻¹(x) for this one

to solve fr the invers
replace f(x) with y
switch x and y
solve for y
replace y with f⁻¹(x)

I'm assuming your thing is $f(x)=log_2(x+4)$

remember

$log_a(b)=c$ translates to $a^c=b$

so
if we replace y with f(x)
$y=log_2(x+4)$
switch
$x=log_2(y+4)$
translate
$2^x=y+4$
minus 4
$2^x-4=y$
$f^{-1}(x)=2^x-4$
evaluate
$f^{-1}(3)=2^3-4$
$f^{-1}(3)=8-4$
$[f^{-1}(3)=4$

it equals 4

Answer 2

F^-1(3)= 2^3-4=8-4=4
Hope this helps.