How do you find the inverse of g(x) = (x -5)^2g(x)=(x5)2?

1 Answer
May 30, 2018

g^-1(x) =5+sqrt(x )g1(x)=5+x

or

g^-1(x) =5-sqrt(x )g1(x)=5x

Explanation:

g(x) = (x -5)^2g(x)=(x5)2

y = (x -5)^2y=(x5)2

Switch the xx and yy:

x = (y -5)^2x=(y5)2

solve for xx:

+-sqrt(x )= sqrt((y -5)^2)±x=(y5)2

+-sqrt(x )= y -5±x=y5

y=5+-sqrt(x )y=5±x

Now you have the problem that this inverse is not a function unless you restrict its range.

g^-1(x) =5+sqrt(x )g1(x)=5+x

or

g^-1(x) =5-sqrt(x )g1(x)=5x