Question

Can sometime tell me why the discriminate b^2-4ac doesn't identify trinomial 3x^2+4x-15 as something that's factorable with two answers? I keep getting a negative number using the discriminate.

Answer 1

Answer: Discriminant = 196

Step-by-step explanation:

y = 3x² + 4x - 15

   a=3    b=4   c=-15

Discriminant = b² - 4ac

                     =(4)² - 4(3)(-15)

                     = 16 - (-180)

                     = 16 + 180

                     = 196

If b² - 4ac > 0, then there are 2 real roots/solutions/x-intercepts

If b² - 4ac = 0, then there is 1 real root/solution/x-intercept

If b² - 4ac < 0, then there are 0 real roots/solutions/x-intercepts

                                                (2 imaginary roots/solutions)

Since 196 is positive, there are 2 real roots ....