Question

Which function is the best inverse of f(x)=x2-9

Answer 1

The inverse is sqrt(x+9)

Explanation:

f(x)=x^2-9

To find the inverse of the function, we interchange x and y and solve for y

y = x^2 -9

x = y^2 -9

Add 9 to each side

x+9 = y^2 -9+9

x+9 = y^2

Take the square root of each side

sqrt(x+9) = sqrt(y^2)

sqrt(x+9) = y

f^-1 (x) = sqrt(x+9)