Respuesta :

follow these steps:

1) y-4=7x^2

2) (y-4)/7 = x^2

[tex] x = \sqrt{ \frac{y - 4}{7} } [/tex]

so you must inverse x and y names:

[tex] {f}^{ - 1} (x) = \sqrt{ \frac{x - 4}{7} } [/tex]