How do I integrate (sqrt(x-2))(x^{2 }+ x + 1) I've got a feeling it's some basic method of integration that I'm forgetting, but I can't find anything like it in my notes.
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substitute :
I tried that. It doesn't really get me anywhere.
Originally Posted by necromanzer52 It doesn't really get me anywhere. It should. Post your working?
u = rt(x-2) du/dx = (1/2)(x-2)^(1/2) = 1/(2(rt(x-2))) (2(rt(x-2))du = dx Subbing that back in gives me : u((x^{2} + x + 1)/((2(rt(x-2))) du I could cancel out the u to get (1/2)(x^{2} + x + 1) du, but that's no use.
I would differentiate it in the form to get You can also then rearrange to get then it all comes out nicely when you sub in.
Originally Posted by necromanzer52 How do I integrate (sqrt(x-2))(x^{2 }+ x + 1) I've got a feeling it's some basic method of integration that I'm forgetting, but I can't find anything like it in my notes. Start by writing Now rewrite the integrand as Now if you make the substitution the integral becomes Can you go from here?
I can go from there alright. I don't really follow you after you wrote "Now rewrite the integrand as". They're multiplying rather than dividing. But the other guys method works fine. So I'm grand.
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