Friday, February 10, 2012

integrating with double angles confuse me. and is it 2u or 3u? i shall have my own way doing those questions...and we don't have school on monday, so my questions remained unanswered for 4 days ):
i wish someone gave me worked solutions. i learn from worked solutions, not just answers.

the house i much quieter without my brother.

someone put iceblocks in the fridge today! and i had my free in the middle of the day and it made my day better (: i managed to find a frozen one at the back of the fridge...
people are so generous (:
if happy stuff appears during the middle of the day, i could pass yr 12 happily...i guess...

and just watched (500) days of summer (an hour ago...)
thought it was good the first time. it's actually pretty crap the 2nd time ): like nothing happens... ):

1 comment:

  1. Like Sin(2A)? Or Cos(2A)?

    To integrate Cos(2A) dA

    Let x = 2A

    dx/dA = 2

    dA = dx/2

    So you get

    Integral of Cos(x) dx/2

    Move 2 outside

    You get 1/2 the integral of Cos(x)

    = Sin(x)/2 + c

    But x = 2A

    Therefore, Sin(2A)/2 + c

    And this would be better on paper, so I guess, get someone to teach you properly.


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