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Resolue x^2+1/(x-2)(x^2+4) fractions |
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Answer» Answer: Since x 2 +2 can not be FACTORED So, (x−1)(x 2 +2) 2x 2 +3x+4
= x−1 A
+ x 2 +2 BX+C
Now cross multiply, 2x 2 +3x+4=A(x 2 +2)+(Bx+C)(x−1) ⇒2x 2 +3x+4=A(x 2 +2)+Bx 2 −Bx+Cx−C ⇒2x 2 +3x+4=(A+B)x 2 +(C−B)x+(2A+C) Comparing the COEFFICIENTS, A+B=2.....(1),C−B=3......(2) and 2A−C=4.......(3) Adding the three equations, we get 3A=9⇒A=3 From (1), A+B=2⇒3+B=2⇒B=−1 From (3), 2A−C=4⇒6−C=4⇒C=2 A=3,B=−1,C=2 Hence, (x−1)(x 2 +2) 2x 2 +3x+4
= x−1 3
+ x 2 +2 −x+2
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