Question

Evaluate the definite integral. Use a graphing utility to verify your result.
π/2 esin 3πx cos 3πx dx

Answer 1

im trying to do u subsittion

Answer 2

Are pi/2 and e the limits of integration?

Answer 3

http://www.wolframalpha.com/input/?i=integral+sin%283*pi*x%29*cos%283*pi*x%29+dx+from+pi%2F2+to+e

Answer 4

\[\int_?^{{\frac{\pi}2}}e^{\sin(3\pi x)}\cos(3\pi x)dx\]

Answer 5

i am gong to bet that the lower limit is zero. that is just a guess. this would be an easy set up for u - sub

Answer 6

no the limits of integration atre pi/2 and zero. the rest is the function to evalutate
i did e^u and let u=sin3pix and then im stuck

Answer 7

ah ok thought so

Answer 8

you are in good shape.

Answer 9

okay my s compute session is going ot end sooon OH NOW .

Answer 10

okay my s compute session is going ot end sooon OH NOW .

Answer 11

\[u=\sin(3\pi x)\]
\[du=3\pi \cos(3\pi x)dx\]

Answer 12

http://www.wolframalpha.com/input/?i=integral+esin%283*pi*x%29*cos%283*pi*x%29+dx+from+zero+to+pi%2F2

Answer 13

that aint is. try this one for a quick answer
http://www.wolframalpha.com/input/?i=integral+e^%28sin%283*pi*x%29%29*cos%283*pi*x%29+dx+from+zero+to+pi%2F2

Answer 14

change limits of integration
\[u(0)=\sin(0)=0\]
\[u(\frac{\pi}{2})=\sin(\frac{3\pi^2}{2})\]
then
\[\frac{1}{3\pi}\int_0^{\sin(\frac{3\pi^2}{2})}e^udu\]

Answer 15

get
\[\frac{e^{\sin(\frac{\pi^2}{2})}-1}{3\pi}\]

Answer 16

thanks sooo much sorry i was at a public computer earlier and my session ended