1. ## Trigonometric integral Answer help

I did my best but im a little sketchy on U-Substitution still
Integrate: Cos7t*sqrt(1-sin7t) dt

Using U substitution i came up with the answer 2/21(1-sin7t)^(3/2) + c
Is this correct.

2. Originally Posted by x5pyd3rx
I did my best but im a little sketchy on U-Substitution still
Integrate: Cos7t*sqrt(1-sin7t) dt

Using U substitution i came up with the answer 2/21(1-sin7t)^(3/2) + c
Is this correct.

$\displaystyle u=1-Sin(7t)$

$\displaystyle \frac{du}{dt}=-Cos(7t)\frac{d}{dt}7t=-7Cos7t$

$\displaystyle -\int{\sqrt{u}\ \frac{du}{7}}=-\frac{1}{7}\int{\sqrt{u}}du$

$\displaystyle =-\frac{1}{7}\frac{2}{3}(1-Sin7t)^{\frac{3}{2}}+C$

3. Thank you and.. by any chance, seeing that your a senior member could you give me a quick tutorial or point me in the right direction on how to use the output you used?

4. Originally Posted by x5pyd3rx
Thank you and.. by any chance, seeing that your a senior member could you give me a quick tutorial or point me in the right direction on how to use the output you used?
http://www.mathhelpforum.com/math-he...-tutorial.html