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    who else can't wait til P3 is over!
    I'm having trouble differentiating and integrating things like sin^2 (1/2x), tan^2 (2x) etc. Does anyone have some kind of list to help me?!

    thanks x
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    Sounds like you need to know your trig identities.

    cos2x = 2cos²x - 1
    cos2x = 1 - 2sin²x

    tan²x + 1 = sec²x
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    (Original post by jazzyj)
    who else can't wait til P3 is over!
    I'm having trouble differentiating and integrating things like sin^2 (1/2x), tan^2 (2x) etc. Does anyone have some kind of list to help me?!

    thanks x
    For differentiation of those, use the chain rule:

    d/dx [(tan 2x)^2] = 2(tan 2x).2(sec 2x)^2 = 4tan 2xsec^2 2x

    d/dx [(sin 0.5x)^2] = 2(sin 0.5x).0.5cos 0.5x = sin 0.5xcos 0.5x

    For integration, you use identities, as queen-of-pain said.
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    so because of the identity sin^2x + cos^2x = 1, does that work when it's sin^2 (2x) i.e. does sin^2 (2x) = 1 - cos^2 (2x)?
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    (Original post by jazzyj)
    so because of the identity sin^2x + cos^2x = 1, does that work when it's sin^2 (2x) i.e. does sin^2 (2x) = 1 - cos^2 (2x)?
    Yes.
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    (Original post by jazzyj)
    who else can't wait til P3 is over!
    I'm having trouble differentiating and integrating things like sin^2 (1/2x), tan^2 (2x) etc. Does anyone have some kind of list to help me?!

    thanks x
    Cos2x=1-ssin^2x therefore:

    (1-cos2x)/2 =sin^2x

    x=(x/2) therefore

    (1-cosx)/2 = sin^2(x/2) then just integrate (1-cosx)/2 = (x-sinx)/2 + c
 
 
 
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