Let


Put


A(1+x2)+Bx(1-x)+C(1-x) =2


Put x=1


2=2A+0+0


A=1


Put x=0


2=A+C


C=2-A


C=2-1=1


Putting x=2


We have 2=5A-2B-C


2=5×1-2B-1


2B=2


B=1





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