please help!!!!! I need to int sec^4(3x) tan^3(3x) dx

[wxchick_H3]

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| sec^4(3x) tan^3(3x) dx
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I need to integrate this, but dont even know where to begin, could someone please give me a hint on where to start. [/list]

 

[skeeter]

\(\displaystyle \L \sec^4(3x) \tan^3(3x) =\)

\(\displaystyle \L \sec^2(3x)\sec^2(3x)\tan^3(3x) =\)

\(\displaystyle \L \sec^2(3x)[1 + \tan^2(3x)]\tan^3(3x) =\)

\(\displaystyle \L \tan^3(3x)\sec^2(3x) + \tan^5(3x)\sec^2(3x)\)

now ... use a substitution to integrate

\(\displaystyle \L \int \tan^3(3x)\sec^2(3x) dx + \int \tan^5(3x)\sec^2(3x) dx\)