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If `int(xe^(x))/(sqrt(1+e^(x)))dx=f(x)sqrt(1+e^(x))-2logg(x)+C`, thenA. `f(x)=x-1`B. `g(x)=(sqrt(1+e^(x))-1)/(sqrt(1+e^(x))+1`C. `g(x)=(sqrt(1+e^(x))+1)/(sqrt(1+e^(x))-1)`D. `f(x)=2(x-2)` |
Answer» Correct Answer - B::D `int(xe^(x))/(sqrt(1+e^(x)))dx` `=x(sqrt(1+e^(x)))-2intsqrt(1+e^(x))dx` `=2xsqrt(1+e^(x))-2int(2t^(2))/(t^(2)-1)dt" "("Putting t"=sqrt(1+e^(x)))` `=2xsqrt(1+e^(x))-4(t+(1)/(2)ln.(t-1)/(t+1))+C` `2xsqrt(1+e^(x))-4(sqrt(1+e^(x)))-2ln.(sqrt(1+e^(x))-1)/(sqrt(1+e^(x))+1)+C` |
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