Question

If (×+1 ) and(×+2) are factors of the expressionx^4+ax^2+b , find the value of and b, with these value of and factorize completely.​

Answer 1

Explanation:

(x⁴+ax²+b) ÷ (x+1) = x³-x²+(a+1)x-(a+1) remainder b+(a+1)

Since x+1 is a factor, b+(a+1) = 0.

(x³-x²+(a+1)x-(a+1)) ÷ (x+2) = x²-3x+(a+7) remainder -3a-15

Since x+2 is a factor, -3a-15 = 0

a = -5

b = 4

x⁴+ax²+b = x⁴ - 5x² + 4 = (x²-4)(x²-1) = (x+2)(x-2)(x+1)(x-1)