How do you find f^-1(x)f1(x) given f(x)=-1/x^2f(x)=1x2?

1 Answer
Apr 1, 2018

f(x)^-1=+-sqrt(-1/x)f(x)1=±1x

Explanation:

You substitute the x values for the y values

x=-1/y^2x=1y2

Then we rearrange for y

xy^2=-1xy2=1

y^2=-1/xy2=1x

y=+-sqrt(-1/x)y=±1x

Such a function doesn't exist as you can't have a negative root on the RR plane. Also it fails the function test as you have two x values corresponding to 1 y value.