calc

Quick calc question guys... What's the integral of cos(x^3)?  Thanks in advance.

how 2 integrate sinx guize?

-sin(x^3)*3x^2

>>3
damn, forget that
http://integrals.wolfram.com/index.jsp?expr=cos(x^3)&random=false
maybe that will help

First you have find a trigonometric identity. Once you find the correct one, integrate using u-substitution to get your final answer.

Here's a hint, [math] sin^2(x) + cos^2(x)= 1

>>5
Wouldn't that only work if I was trying to integrate cos^3(x)?

>>6
Yes, that method would only work if it was cos^3(x).

cos(x^3) =/= cos^3(x)

You're going to get quite the integral from this thing

If you try using Euler's formula you run into e^(x^3), which is some permutation of the Exponential Integral.

If you do it directly, you have to deal with the Incomplete gamma function. Since I've never dealt with either of those, I can't really give you a 'quick' answer.

>>4
is the correct answer. >>5, >>2, and >>3 don't have a clue.

>>3
>>4
also a third option: maclaurian series, make sure it's in summation notation or a very high order.

I took a shot at this and failed.  Don't care to go on but the exponential form has the most promise.  I think by hand you can find it without gama but don't take my word on that.