## anonymous 4 years ago my Question : Integral 1 / x (root (3+x^2)

1. anonymous

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2. agreene

why do you keep coming up with integrals I don't want to do. another trig sub question O.o

3. anonymous

angreene What can I do.. all my subject like this Q..

4. agreene
5. anonymous

$\int\limits_{1}^{2}1/(x(3+x^2)^(1/2))$ let u = 3+x^2 du= 2xdx (1/2)(1/u)^(1/2)]du (1/2) 2u^(1/2) =u^(1/2) when x = 1 u =4 and when x = 2 u = 7 therefore =7^(1/2)-2^(1/2)

6. anonymous

no i'm wrong

7. agreene

1/(x sqrt(x^2+3)) substitute x = sqrt(3) tan(u) and dx = sqrt(3) sec^2(u) du. which is why i didnt want to do this one, lol

8. anonymous