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FP3 integration

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Hi guys

Can anyone help me with Question 12? a? I tried what the question suggested but didn't know what to do next.

any reply will be appreciated. Thanks


Posted from TSR Mobile
Reply 1
Original post by 123321123

Hi guys

Can anyone help me with Question 12? a? I tried what the question suggested but didn't know what to do next.

any reply will be appreciated. Thanks


Posted from TSR Mobile


IBP with tannx=tan2xtann2x=(sec2x1)tann2x=sec2tann2xtann2x\tan^n x = \tan^2 x \tan^{n-2} x = (\sec^2 x - 1)\tan^{n-2} x = \sec^2 \tan^{n-2} x - \tan^{n-2}x

So tannxdx=[tann1xn1]0π/4In2\displaystyle \int \tan^n x \, \mathrm{d}x = \bigg[\frac{\tan^{n-1} x}{n-1} \bigg]_0^{\pi/4} - I_{n-2}

By using the reverse chain rule on sec2xtann2xdx\int \sec^2 x \tan^{n-2} x \, \mathrm{d}x.
(edited 8 years ago)
Reply 2
Original post by Zacken
IBP with tannx=tan2xtann2x=(sec2x1)tann2x=sec2tann2xtann2x\tan^n x = \tan^2 x \tan^{n-2} x = (\sec^2 x - 1)\tan^{n-2} x = \sec^2 \tan^{n-2} x - \tan^{n-2}x

So tannxdx=[tann1xn1]0π/4In2\displaystyle \int \tan^n x \, \mathrm{d}x = \bigg[\frac{\tan^{n-1} x}{n-1} \bigg]_0^{\pi/4} - I_{n-2}

By using the reverse chain rule on sec2xtann2xdx\int \sec^2 x \tan^{n-2} x \, \mathrm{d}x.


thanks so much, i understand it now.
Reply 3
Original post by 123321123
thanks so much, i understand it now.


Cool.

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