Question

Which of the following is a polynomial with roots: − square root of 5 , square root of 5 , and 3? (6 points)

A) x3 − 3x^2 − 5x + 15
B) x^3 + 2^x2 − 3x − 6
C) x^3 − 2x^2 − 3x + 6
D) x^3 + 3x^2 − 5x − 15

Answer 1

Let's check the first polynomial , that is

`P(x)= x^3 -3x^2 -5x+15`

We need to factor it first and for that we have to do grouping and factoring .

`image`

TO find the roots, we need to set P(x) to 0, that is

`image`

SO the correct option is A .