Question

By using factor theorem show that X +2 is a factor of polynomial 3X cube minus X square -20 X -12

Answer 1

Answer:

3x^3-x^2-20x-12

to check if x+2 is a factor of given equation or not so put x+2=0 which gives x= -2

f(-2) = 3(-2)^3-(-2)^2-20(-2)-12

= -24-4+40-12

= -40+40

= 0

This implies x+2 is a factor of given equation