#Calculus II: Trigonometric Integral

12 messages · Page 1 of 1 (latest)

vapid swift
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I'm a bit confused as to why I need to add 1/4 and 4 to the integral and get (2sinxcosx)^2. Why can't I just sqrt the original integral instead and evaluate from (sinxcosx)^2 instead?

wise epochBOT
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patent cloud
vapid swift
vapid swift
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Yes, I understand, but I don't understand how to get 1/4 and 4. I see that it was added in to make it form correctly, but I don't understand why and the choosing of it. I don't understand the rule of adding 1/4 and 4 into the integral.

patent cloud
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you need to multiply by 1 to make the integral not change, and they just wanted 4sin^2(x)cos^2(x)

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to get sin^2(2x)

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so you need to also insert a 1/4 to balance it

vapid swift
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Ohhhhh. Thank you so much! You are a life saver! Thank you, thank you!

Would that work with any number like 1/16 and 16, or would it need to be exactly 1/4 and 4??

patent cloud
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you can insert any inverse pair (except 0 ofc)