Question

Evaluate the expression for the given values of x. ​

Answer 1

The values are as follows:

20

11

2

-1

8

Explanation:

We are given the polynomial
`$ x^3 + 3x^2 - 7x + 2 $`

To find the value of the polynomial for different values of 'x' simply substitute the given value of x, to determine the answer.

(i) x = -2.

⇒
`$ (-2)^3 + 3(-2)^2 - 7(-2) + 2 = -8 + 12 + 14 + 2 = -8 + 28 $`

= 20.

The value of the polynomial at x = -2 is 20.

(ii) Similarly, x = -1.

`$ (-1)^3 + 3(-1)^2 - 7(-1) + 2 = -1 + 3 + 7 + 2 = -1 + 12 $`

= 11

(iii) x = 0

`$ 0 + 0 + 0 + 2 $`

= 2

(iv) x = 1

`$ 1^3 + 3(1)^3 - 7(1) + 2 = 1 + 3 - 7 + 2 = 6 - 7 $`

= -1

(v) x = 2

`$ 2^3 + 3(2)^2 - 7(2) + 2 = 8 + 12 -14 + 2 $`

= 8.