Question

Find the inverse of the function.
y = 2x2-4

Answer 1

Explanation:

x and y trade places.

y = 2x² - 4

y + 4 = 2x²

x² = (y + 4)/2

x = ±sqrt((y + 4)/2)

and for the usual notation we rename x to y and vice versa

y = ±sqrt((x + 4)/2)

and this is not a function, because there are now 2 result values for every input value.