Question

How to use the discriminant to find out how many real number roots an equation has for `4x^2 -4x -1 = 0`?

Answer 1

`D = d^2 = 16 + 16 = 32 -> d = +-4sqrt2`

There are 2 real roots (2 x-intercepts).

`x = 4/8 +- (4sqrt2)/8 = 1/2 +- (sqrt2)/2`