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That last one is exclusive content btw (made it myself).
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Thanks guys. This is the friend that Raithed posted for
I have 1, 2, 3, 4, 6, 10, and 14 done
Not quite sure how to go about the rest of these. Any ideas?
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The flowchart should help with some of them. Remember, sin^2 = 1 - cos^2 and cos^2 = 1 - sin^2. That means if a power is odd you can
cos^3 = cos cos^2 = cos (1 - sin^2)
then u = sin, du = 1/cos dx.
For the rational ones do partial fractions.
edit: also, you can use http://integrals.wolfram.com/index.jsp to check your work
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My trig is terrible - for example, I would have no idea how to get about #9.
i did 4 times the integral (sec^2 x) ^2
which then became sex^2 x (tan ^2x + 1)
is this the right approach to be taking? If so , what is the proper next step?
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damn i wish i had that shit fight/flight posted when i took calc :{
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you can do most of these by parts or trig identities
for 9. "which became sex^2x" ahah i see what you did there ^_^ sec^2(x)tan^2(x) function to a power times its derivative and S sec^2(x) dx = tanx
well at least i'm pretty sure how it is i forgot all this shitty trig identity integration stuff
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so then you have u = tan, then the derivative of u, du, becomes dx = 1/sec^2 du.
then its the integral of u^2 + 1 = 1/3 u^3 + u
or 1/3 (tanx)^3 + tanx
giving 4/3 (tanx)^3 + 4tanx
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you don't need to use u-substitution on that one right?
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Thanks, fight_or_flight. Do you have any idea on how to go about #5? (Do you have AIM, MSN, or YIM and don't mind me messaging you for help?)
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actually, I should be doing other things besides this, and I have to go home soon. Anyway, I haven't taken calc in a long time so these problems are hard for me too, lol.
Basically I've just been working off my own flowchart to be honest.
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Any ideas on how to do the 2nd integral of 3, 5, 11, 12, 13, 15, 16, 17, 18, and 19?
The second integral of #3 being what happens after you split the fraction and are left with 18x over the denominator
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On April 02 2008 12:55 doob10163 wrote: Any ideas on how to do the 2nd integral of 3, 5, 11, 12, 13, 15, 16, 17, 18, and 19?
The second integral of #3 being what happens after you split the fraction and are left with 18x over the denominator separate it into 2 fractions 1/(1+3x^2) and -6x/(1+3x^2) after you take out the 3 1st one is arctan 2nd one is function to a power times its derivative
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number 5: u-sub u=lnx du=dx/x x=e^u then use parts (tabular method)
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11 is just trig sub... it's really straightforward...idk why it's hard? sec(theta) = sqrt(4y^2+1), dy=(sec^2(theta))d(theta)/2
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