Integration (1 Viewer)

tommykins

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divide all terms by cos^2 x, have u tried that?

PS. doing from observation, cbf doing ti all.
 

cutemouse

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Yeah I did that... But then when I let u=tanx, the upper limit is pi/2, which doesn't exist for tan.

So..?
 

lolokay

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ha. maybe say that the integral gives the same value if the upper limit was (pi/2 - h) as h -> 0, h > 0 or something? i dono

edit: or break the initial integral into two integrals, one of which contains the 0 limit, and the other has the pi/2 limit. so then you can divide by cos^2x for the first one, and sin^2x for the second so you avoid both cot0 and tan(pi/2) ?
 
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cutemouse

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I figured it out... I had to take limits, this would be a nice 'novice separator' question in a trial lol...
 

Trebla

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Remember the inverse tan of infinity is pi/2...
 

lolokay

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why not negative infinity, or -pi/2 for the inverse? (ie. isn't inverse tan not defined for pi/2? its range is -pi/2 < x < pi/2)

edit: though i guess you could say that since the function is always positive, it could only be pi/2
 
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Trebla

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Ok, if you want to get technical, then as x approaches infinity, tan-1x approaches pi/2
 

cutemouse

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Hi guys,

Seriously last question until next week :p...



Tried letting and miserably failed :(

Thanks
 

study-freak

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Which are now standard integrals.
Tell me if I did anything wrong.
 

Ppen

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Just a question. How do u guys type in mathmatical notation (i.e the integrals)? Is there a program for it?
 

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