Integrate :-
|dw:1375899377465:dw| @Fifciol
Break the \[\tan ^3(x) = \tan^2(x)\tan(x)\] then integrate by parts. See if that helps
∫tan³x dx= ∫tan²x tanx dx =∫(sec²x−1)tanx dx =∫sec²xtanx dx − ∫tanx dx Put u=tanx, then du/dx=sec²x, du=sec²xdx =∫u du − ∫tanx dx =u²/2 − log|secx| + C =(tan²x)/2 − log|secx| + C from yahoo answers
or use UV method
Ok...
\[\int\limits \tan^3xdx=\int\limits \tan^2*\tan xdx=\int\limits \frac{ \sin^2x }{ \cos^2x }\tan xdx=\int\limits \tan x \frac{ 1-\cos^2x }{ \cos^2x }dx\]= \[\int\limits \tan x(\frac{ 1 }{ \cos^2x }-1)dx=\int\limits \frac{ \tan x dx }{ \cos^2 x }-\int\limits tanx dx\]
Taking U=(tanx)^3 and V=1!!
substitute u=tanx du=1/cos^2 x
so\[\int\limits udu=\frac{ u^2}{ 2 }+C=\frac{ \tan^2x }{ 2 }+C\]and\[\int\limits \tan xdx=\ln(cosx)+C\]
yw bro :)
Thank you .... I am a girl... Okay
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