| someone posted this problem and my
solution followed
solve
∫_0 ^1 ((ln(x+(√(1+x^2 ))))/(√(1+x^2 )))dx
solution
y=ln(x+(√(1+x^2 ))) and dy=(1/(√(1+x^2 )))dx
at x=0,y=0 and at x=1,y=ln(1+(√2))
hence
I=∫_0 ^(ln(1+(√2))) (y/(√(1+x^2 )))×(√(1+x^2 ))dy=∫_0 ^(ln(1+(√2))) ydy
I=[(y^2 /2)]_0 ^(ln(1+(√2))) =(1/2)ln^2 (1+(√2))
∵∫_0 ^1 ((ln(x+(√(1+x^2 ))))/(√(1+x^2 )))dx=(1/2)ln^2 (1+(√2))
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