Question

Let f(x) = x^2 – 81. Find f–1(x). Can someone double-check what I have?

Answer 1

I hope this helps you



y=x^2-81


x^2=y+81


x=square root of y+81


f^-1 (x)= square root of x+81

Answer 2

For the answer to the question above, if you are just checking your answer, I'll just show the solution. Is it just ok?
f(x) = x2 - 81 
y = x^2 - 81 
x = y^2 - 81 
x + 81 = y^2 
y = ± √(x + 81) 

f⁻¹(x) = ± √(x + 81) answer

Answer is ±√x+81

I hope I helped you with my answer somehow.