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Homework Statement
Evaluate integral sqrt(x^2-9)/x dx
Homework Equations
The Attempt at a Solution
I get this for my answer sqrt(x^2-9)+3sin^(-1)(3/x)+c which is apparently wrong because when I take the derivative of it I don't get the integrand
my work is a attachment in this post
wolfram alpha claims the answer is
sqrt(x^2-9)+3tan^(-1)(3/sqrt(x^2-9))
http://www.wolframalpha.com/input/?i=integral+sqrt%28x^2-9%29%2Fx+dx
I'm not sure if I'm doing something wrong, i think i am doing something wrong becasue when I take the derivative I don't get the integrand but I don't see what I'm doing wrong
thanks for any help