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Calculus/Trig Substitution

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Expert: - 4/24/2008


Question

Trig Substitution
I have performed a trig substitution on this
integral.
My Book answer is:

-Arctan[1/sqrt(x^2-1)]

(Thats right negative Arctan)

Any idea where I went wrong ?

Thank
Mark

Answer
I tried doing this problem and I got the same thing.  The answer is 1, the integral is theta, and substituting it back in gives the answer to be arctan((x^2 - 1)^0.5).  I think the only thing we're missing is the +C.

Note that if this problem involved a log, -lox(x)=log(1/x), but that's not the case.

I find what you're doing is write and the book made a mistake on that one.  If you're taking a trig class ask the professor or teacher.  Maybe you could go to his office and ask him there.

That's the answer you'll get from me.  Please send me the correct answer if we both missed something.

Thanks!
    Questioner's Rating
    Rating(1-10)Knowledgeability = 10Clarity of Response = 10Politeness = 10
    CommentThanks for the confirmation. By the way it is also of the trig inverse form. And I get the same answer after a little minuplulation. Thanks again


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