TS ICET 23 May 2018 Shift 2 Paper

© examsiri.com

Question : 124 of 200

Marks: +1, -0

If the polynomial

\x^3 + 10\x^2 +\ax + b

is exactly divisible by (x-1) and (x+2) then a - b =

9
-9
-25
25

Solution:

Let

f(x)=x^{3}+10 x^{2}+a x+b

Given

f(1)=0 ⇒ 1+10+a+b=0

⇒ a+b=-11

→(1)

f(-2)=0 ⇒-8+40-2 a+b=0

⇒-2 a+b=-32

→ (2)
Solving (1) & (2),

a = 7, b = –18

a-b = 7- (-18) = 25.

© examsiri.com

Go to Question:

Prev Question

Next Question