Question

If (x2 - 1) is factor of ax4 + bx3 + cx2 + dx + e then the value of a +c+e is?​

Answer 1

Answer:

b+d

Step-by-step explanation:

Since x2 - 1 = (x - 1) is a factor of

p(x) = ax4 + bx3  + cx2 + dx + e  

∴ p(x) is divisible by (x+1) and (x-1) separately  

⇒ p(1) = 0 and p(-1) = 0

p(1) = a(1)4 + b(1)3 + c(1)2 + d(1) + e = 0

⇒  a + b + c + d + e = 0 ---- (i)  

Similarly, p(-1) = a (-1)4 + b (-1)3  + c (-1)2 + d (-1) + e = 0

⇒ a - b + c - d + e = 0  

⇒ a + c + e = b + d