Question

How do you find the zeros of `y = -9x^2 + 18x -2` using the quadratic formula?

Answer 1

(3 +- sqrt7)/3

Explanation:

Use the improved quadratic formula (Google Search)
`y = -9x^2 + 18x - 2 = 0`
`D = d^2 = b^2 - 4ac = 324 - 72 = 252 = 36(7)` --> `d = +- 6sqrt7`
There are 2 real roots:
`x = -b/(2a) +- d/(2a) = -18/-18 +- (6sqrt7)/18 = 1 +- sqrt7/3`
`x = (3 +- sqrt7)/3`