Question

8.
IF (21+1) is the factor of the polynomial p(t)=48+41-t-1 then the value of
is :
1
1
2.
(A)
(B)
(C)
1
0
(D)
2​

Answer 1

Answer:

Since, x+1 is a factor of p(x)=2x

3

+ax

2

+2bx+1

Then, by factor theorem, p(−1)=0

⇒−2+a−2b+1=0⇒a−2b=1                      ...(i)

Also,2a−3b=4                                                            ...(ii)

On multiplying (i) by 2 and (ii) by 1, we get

2a−4b=2

−

2

​

a

+

−

​

3b=

−

4

​

​

    −b=−2

∴b=2

On putting b=2 in (i), we get

a−2×2=1⇒a=5

∴a=5,b=2    

Step-by-step explanation: