Question

Find the inverse of the function. y=x2 + 4x + 4

Answer 1

Answer: To find the inverse of the function, we need to make x as a function of y and at the final step make a switch between x and y (i.e. make x as y and y as x)

y = x² + 4x + 4  ⇒⇒⇒ factor the quadratic equation

y = (x+2)(x+2)

y = (x+2)²         ⇒⇒⇒ take the square root to both sides

√y = x+2

x = √y - 2         ⇒⇒⇒ x becomes a function of y

final step:

∴ y = √x - 2   ⇒⇒⇒ the inverse of the given function

So, as a conclusion:

f(x) = y = x² + 4x + 4  ⇒⇒⇒ the given function

f⁻¹(x) = y = √x - 2       ⇒⇒⇒ the inverse of the given function