Question

F(x)= 3x^2+45
What does x equal?

Answer 1

`x=\sqrt{(y-45)/(3)}`,
`x=-\sqrt{(y-45)/(3)}` for
`y>45`

Explanation:

Apply the rule that f(x) = y into the equation to then get:

y = 3x^2+45 ⇒ Then solve for x

The image below shows step-by-step on how to solve it ↓

Hope this helps! :)

Answer 2

Solve the equation for x by finding a,b,c of the quadratic then applying the quadratic formula.
x =±i√ 15