Write the inverse of f (x) = x2+4

F (x) = x² + 4

y = x² + 4

First, I reverse the equation to be

x² + 4 = y

Second, we need only x to remain on the left side and we need to move the others to the right side

x² + 4 = y

x² = y - 4

x = √ (y - 4)

Last, change into invers function

f⁻¹ (x) = √ (x - 4)