Question

If (x+1) is a factor of px^3 + x^2 - 2x + 9, then find the value of p.

Answer 1

Answer:

px3 + x2 – 2x – q is divisible by (x – 1) and (x + 1) ⇒ p(1)3 + (1)2 – 2(1) – q = 0 ⇒ p – q = 1 ...(i) and p(–1)3 + (–1)2 – 2(–1) – q = 0 ⇒ p + q = 3 ...(ii) Solving (i) and (ii) p = 2, q = 1.Read more on Sarthaks.com - https://www.sarthaks.com/1000672/if-the-expression-px-x-2-2x-q-is-divisible-by-x-and-x-1-then-the-values-of-p-and-respectively-are

Answer 2

Since x+1 is a factor of px³ +x² -2x +9 , by remainder therom we can say that the polynomial will be equal to zero at X=-1.

On putting x=-1 , we get our polynomial as -p+1+2+9 =0

So p= 12 , hope it helped you…