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

Answer:

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#