Question

The value -2 is a lower bound for the zeros of the function shown below.

f(x) = 4x^3 – 12x^2 – x + 15

A) True
B) False​

Answer 1

False

Explanation:

f(x) = 4x³ - 12x² - x + 15

Set output to 0.

Factor the function.

0 = (x + 1)(2x - 3)(2x - 5)

Set factors equal to 0.

x + 1 = 0

x = -1

2x - 3 = 0

2x = 3

x = 3/2

2x - 5 = 0

2x = 5

x = 5/2

-2 is not a lower bound for the zeros of the function.