Question

Use the discriminant to determine the nature of the roots of -6x^2 - 12x + 90 = 0.

a.no real root
b.two distinct real roots
c.one distinct real root
d.three distinct real roots

Answer 1

The roots are x=-5 and +3. So answer is b.

Answer 2

The reason is in this case D>0 (12^2-4(-6)(90) = 144+2160=2304>0