Question

pls tell the 9th question

Answer 1

Let p(x) = ax3 + x2 - 2x + b 
Since (x+1) and (x-1) are the factors of p(x),

∴ p(-1) = 0 and p(1) = 0

∴ p(-1) = a(-1)3 + (-1)2 - 2  (-1) + b = 0
             = - a + 1 + 2 + b = 0
             = a - b = 3                                   ---------------------- (i) 

Again, p(1) = a(1)3 + (1)2 - 2(1) + b = 0
                     = a + 1 - 2 + b = 0
                     = a + b = 1                          ---------------------- (ii) 

Solving equations (i) and (ii) We get,   

a = 2 and b = -1