What I was taught after putting f(x) = y is make x the subject, written in terms of y:then switch x and y
so x = √(2y² + 12)
then rearrange for y
so i get
y = (1/2)√(x² - 12)
could anyone confirm this is right or wrong?
Finally replace x with and y with x:
Note that the plus/minus sign means it's not one to one and so not a function unless the domain is restricted