Hi, in my lecture notes it says: $\displaystyle \int^9_0 2x cos x^2 dx $ equals to $\displaystyle sin x^2 ]^9_0 $ i dont get how they got that can someone please explain it to me in a very simple way?
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Originally Posted by Pengu Hi, in my lecture notes it says: $\displaystyle \int^9_0 2x cos x^2 dx $ equals to $\displaystyle sin x^2 ]^9_0 $ i dont get how they got that can someone please explain it to me in a very simple way? Put x^2 = t, then 2x*dx = dt. The integration becomes Int(cost)dt = sin(t) = sin(x^2)
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