Question

Determine whether −2 is a zero (root) of the function:

f(x) = 2x^3 + x^2 − 10x − 12

Yes

or

No

Answer 1

No

Explanation:

Using factor theorem

If the remainder is 0, it is a root

2(-2)³ + x(-2)² − 10(-2) − 12

-4

Since the remainder is non-zero, it is not a root

Answer 2

The answer to your question is No

Explanation:

Data

function f(x) = 2x³ + x² - 10x - 12

To know if a number is a root of a function, evaluate the function on that number, if the result is zero, then that number is a root.

Substitution

f(-2) = 2(-2)³ + (-2)² - 10(-2) - 12

Simplification

f(-2) = 2(-8) + 4 + 20 - 12

f(-2) = -16 + 4 + 20 - 12

f(-2) = -28 + 24

f(-2) = -4

-2 is not a root that the function.