Question

If both (x + 1 )and ( x - 1 )are factors of x cube + x square - 2 X + b find a and b

Answer 1

Answer:

This is the answer to this sum

Step-by-step explanation:

x-1) and (x+1) are factors of the given polynomial.

x-1 = 0. ; x+1 = 0

x = 1. ; x = -1

Put x= -1,1 to find a and b

First,put x = 1

ax³+x²-2x+b = 0

a(1)³+(1)²-2(1)+b=0

a+1-2+b=0

a+b-1 = 0

a+b = 1 --------(1)

Put x = -1

a(-1)³+(-1)²-2(-1)+b = 0

a(-1)+1+2+b = 0

-a+b+3 = 0

-a+b = -3 -------(2)

(1)+(2)

a+b = 1

-a+b=-3

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2b = -2

b = -2/2

b = -1

Put b= -1 in (1)

a+(-1) = 1

a-1 = 1

a=1+1

a=2

Therefore, a = 2 and b = -1

hope this really helps you out in solving this equation