Question

Which of the following is a polynomial with roots negative square root of 5, square root of 5, and 3?

x3 − 2x2 − 3x + 6
x3 + 2x2 − 3x − 6
x3 − 3x2 − 5x + 15
x3 + 3x2 − 5x − 15

Answer 1

The correct answer is the first one

Explanation:

x3 − 2x2 − 3x +

Use the quadratic equation and you will get a polynomial with roots negative square root of 5, square root of 5, and 3

Answer 2

The polynomial with those roots would be:

y = (x + √5)(x - √5)(x - 3)
▬▬▬▬▬▬▬▬▬▬▬ multiply this out to get
y = (x² - 5)(x - 3)

y = x³ - 3x² - 5x +15