what is the integral of xcos(3x) from 0 to pi/2?

Thank you for the opportunity to help you with your question!

∫xcos(3x)

= x∫cos3x dx + ∫x* -sin 3x/3 dx

=(3xsin(3x) + cos3x) / 9

now apply the limit from 0 to pi/2

=(3 pi sin(3pi) +cos ( 3 pi) ) /9 - (3*0*sin(3*0) + cos3*0) / 9

= (3 pi *0 + -1 ) /9 - (3*0*0 + 1) / 9

= -1/9 -1/9

= -2/9

answer is -2/9

sorry...i thought it was from 0 to pi

the answer for 0 to pi/2

is

=(3 pi sin(3pi/2) +cos ( 3 pi/2) ) /9 - (3*0*sin(3*0) + cos3*0) / 9

= -pi/6 - 1/9

answer is -pi/6 - 1/9

please apologize for my mistake......

hope you understood..please message if you have any doubts...thank you

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