Questions With Integral Calculus

DJChalf
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Homework Statement



find the following integrals.

Homework Equations



1. ∫2x^3 sin(x^2)dx

2.∫ x(2x-3)^1/3dx

The Attempt at a Solution



Using U-Sub for number 2 i ended with ((3(2x-3)^7/3)/28)+((9(2x-3)^4/3)/16)+C

I apologize for the form but I'm new here and don't really know how all the notations work.

The answer I got for problem 2 just looked weird to me and when i try to check the work integrating on my TI-89 i get an error message saying "invalid implied multiply".

Problem 1 I am completely lost on I've tried using substitution but I'm having troubles with what term i should be using...
 
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For (1), first let u= x2, then use integratation by parts.

You have (2) correct.
 
DJChalf said:

Using U-Sub for number 2 i ended with ((3(2x-3)^7/3)/28)+((9(2x-3)^4/3)/16)+C


Do you mean

\frac{3}{28}(2x-3)^{7/3}+\frac{9}{16}(2x-3)^{4/3}+C?

That is wrong.

ehild
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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