Question

How do you solve `3x^2 - 4x - 8 = 0` using the quadratic formula?

Answer 1

`x = +- (2/3)(1 +- sqrt7)`

Explanation:

Use the improved quadratic formula (Google, Yahoo Search)
`D = d^2 = b^2 - 4ac = 16 + 96 = 112 = 16(7)` --> `d = +- 4sqrt7`
There are 2 real roots:
`x = -b/(2a) +- d/(2a) = 4/6 +- 4sqrt7/6 = +- (2/3)(1 +- sqrt7)`