To find the inverse
replace f(x) with y
switch all x and y
solve for y
replace y with f⁻¹(x)
f(x)=x^2-9
y=x^2-9
x=y^2-9
x+9=y^2
sqrt both sides
replace
f⁻¹(x)=
that is the inverse
replace f(x) with y
switch all x and y
solve for y
replace y with f⁻¹(x)
f(x)=x^2-9
y=x^2-9
x=y^2-9
x+9=y^2
sqrt both sides
replace
f⁻¹(x)=
that is the inverse