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Mathematics 7 Online
OpenStudy (thatonegirl_):

integrate

OpenStudy (thatonegirl_):

\[\int\limits_{?}^{?} sinxcos^2x dx\]

OpenStudy (zarkon):

\[u=\cos(x)\]

OpenStudy (thatonegirl_):

wont there still be an x though?

zepdrix (zepdrix):

\[\large\rm \int\limits \sin x (\cos x)^2~dx\]An x where?

OpenStudy (royalranger):

\[\cos ^{2}x=\frac{ 1+\cos2x }{ 2 }\]

zepdrix (zepdrix):

If you make that substitution, what do you get for your differential?\[\large\rm u=\cos x\]\[\large\rm du=?\]

OpenStudy (thatonegirl_):

-sinx

zepdrix (zepdrix):

Yes\[\large\rm du=-\sin x~dx\]

zepdrix (zepdrix):

Do you see how that helps? If not I can color code it.

OpenStudy (thatonegirl_):

OHH

OpenStudy (royalranger):

Oh, now i understand where @zepdrix was going. Use their method.

OpenStudy (thatonegirl_):

Sorry i'm not thinking xD Okay thank you for the help!!

zepdrix (zepdrix):

Half Angle Identity was a clever idea royal :D I think the sine gets in the way though.

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