How do you find the roots, real and imaginary, of y= x^2 - x - (x-9)^2 using the quadratic formula?

1 Answer
Mar 19, 2017

We have real zero of the function, which is 81/17

Explanation:

In the given function as we will see below terms relating to x^2 cancel out and hence, the function is a linear one and not quadratic and we do not need quadratic formula. Let us try to solve this.

y=x^2-x-(x-9)^2

= x^2-x-(x^2-18x+81) - using formula for (a-b)^2

= x^2-x-x^2+18x-81

= cancelx^2-x-cancelx^2+18x-81

= 17x-81

Hence, we have real zero of the function which is 81/17