Question

If both x+1 and x-1 are factors of ax3 +x2 -2x +b , find a and b .

Answer 1

Step-by-step explanation:

Given that (x+1)(x-1) are the factor of the equation ax³+x²-2x+b so,

when x+1 is a factor

x+1=0

x=-1

putting the value of x in the given equation

-a+b+3

-a+b=-3 __________(1)

when x-1 is a factor

x=1

putting again in the equation

a+b-1

a+b=1 ______________(2)

on solving equation (1) and (2) we get,

b= -1

a= 2