Question

Let f(X) = 2x + 2. Solve f^-1(X) when X = 4

Answer 1

basically, x becomes y an y becomes x
inverses
if f(x)=y, then f⁻¹(y)=x

so what you do is evaluate f(4) and that answer is the x in the f⁻¹(x)


f(4)=2(4)+2
f(4)=8+2
f(4)=10

theefor

f⁻¹(10)=4

if you wanted to find inverse
y=2x+2
x=2y+2
x-2=2y

`(x-2)/(2)`=y
f⁻¹(x)=
`(x-2)/(2)`


anyway, f⁻¹(10)=4