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Evaluate:`int1/((x+1)sqrt(x^2-1))dx` |
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Answer» Correct Answer - `sqrt((x-1)/(x+1))+C` `" Let " I=int(1)/((x+1)sqrt(x^(2)-1))dx` ` " Putting " x+1=(1)/(t) " and " dx=-(1)/(t^(2))dt, " we get " ` ` I=int(1)/((1)/(t)sqrt(((1)/(t)-1)^(2)-1))(-(1)/(t^(2)))dt ` `=-int(dt)/(sqrt(1-2t))=-int(1-2t)^(-1//2)dt ` `=-((1-2t)^(1//2))/((-2)((1)/(2)))+C=sqrt(1-2t)+C ` `=sqrt(1-(2)/(x+1))+C=sqrt((x-1)/(x+1))+C` |
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