Question

F(x) = -7x2 + 8x + 2

What is the value of the discriminant of f?
How many x-intercepts does the graph of f have?

Answer 1

120 ; Two

Explanation:

-7x2 + 8x + 2

B² - 4AC

8² - 4(-7)(2)

64 - (-56)

120

Since 120 > 0, the graph will have two distinct x-intercepts

Answer 2

120

2 real intercepts

Explanation:

f(x) = -7x^2 + 8x + 2

The discriminant is

b^2 -4ac

where ax^2 +bx+c

a=-7 b =8 c=2

The discriminant is

8^2 - 4(-7) (2)

64 +56

120

This will have 2 real x intercepts because 120>0