# Find the Inverse y=x^2-18x Interchange the variables.
Solve for .
Rewrite the equation as .
Move to the left side of the equation by subtracting it from both sides.
Use the quadratic formula to find the solutions.
Substitute the values , , and into the quadratic formula and solve for .
Simplify.
Simplify the numerator.
Raise to the power of .
Multiply by .
Multiply by .
Factor out of .
Factor out of .
Factor out of .
Rewrite as .
Rewrite as .
Rewrite as .
Pull terms out from under the radical.
Raise to the power of .
Multiply by .
Simplify .
Simplify the expression to solve for the portion of the .
Simplify the numerator.
Raise to the power of .
Multiply by .
Multiply by .
Factor out of .
Factor out of .
Factor out of .
Rewrite as .
Rewrite as .
Rewrite as .
Pull terms out from under the radical.
Raise to the power of .
Multiply by .
Simplify .
Change the to .
Simplify the expression to solve for the portion of the .
Simplify the numerator.
Raise to the power of .
Multiply by .
Multiply by .
Factor out of .
Factor out of .
Factor out of .
Rewrite as .
Rewrite as .
Rewrite as .
Pull terms out from under the radical.
Raise to the power of .
Multiply by .
Simplify .
Change the to .
The final answer is the combination of both solutions.
Solve for and replace with .
Replace the with to show the final answer.
Set up the composite result function.
Evaluate by substituting in the value of into .
Remove parentheses.
Simplify each term.
Factor using the perfect square rule.
Rearrange terms.
Rewrite as .
Check the middle term by multiplying and compare this result with the middle term in the original expression.
Simplify.
Factor using the perfect square trinomial rule , where and .
Pull terms out from under the radical, assuming positive real numbers.     