Question

Find whether x + 1 is factor of 2 x cube + x square - 2 x -1

Answer 1

f(-1) = 2x^3 + x^2 - 2x - 1

= 2(-1)^3 + (-1)^2 - (-1)

= -2 + 1 + 1

= -2 + 2

= 0

hence (x+1) is a factor of the given polynomial