Fungsi invers dari 3x+6 dan x2-4

f(x)=3x+6
[tex]y = 3x + 6 \\ y - 6 = 3x \\ \frac{y - 6}{3} = x \\[/tex]
f'(x)=x-6/3

[tex] y = {x}^{2} - 4 \\ y + 4 = {x}^{2} \\ x = \sqrt{y + 4} [/tex]
f'(x)=
[tex] \sqrt{y + 4} [/tex]