Question

1. Find a if x³ + ax² - x -8 is divisible by x -1​

Answer 1

a = 8

Explanation:

x-1 = 0

x = 1

let x³ + ax² -x -8 be p(x)

hence, p(1) = (1)³ + a(1)² -1 -8 = 0 (since, x-1 is a factor)

= 1 + a - 1-8

= a - 8 = 0

therefore, a = 8