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hey can someone help me to integrate the following: pleaseee..
(any help appreciated)

(sinx)/(cosx)^4
Original post by going_crazy12
hey can someone help me to integrate the following: pleaseee..
(any help appreciated)

(sinx)/(cosx)^4


To clarify, you do mean sin(x)cos4(x)\dfrac{sin(x)}{cos^4(x)} right?

You can rewrite the function in terms of tan(x) and sec(x) and then use a substitution.
(edited 13 years ago)
Original post by going_crazy12
hey can someone help me to integrate the following: pleaseee..
(any help appreciated)

(sinx)/(cosx)^4


I would convert (cosx)^4 to (cos(x)^2)^2 and then use an identity to change cos into sin, and then make the substitution.
Reply 3
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SimonM
18
Or note that -sin x is the derivative of cos x
Reply 4
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going_crazy12
OP
thnks for the replies guyz but could any of u solve the whole thing.. pls..
Reply 5
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nuodai
17
Original post by going_crazy12
thnks for the replies guyz but could any of u solve the whole thing.. pls..


No, do it yourself :p: There's an "obvious" substitution to make (at least, it's obvious if you spot it), and it's made even more obvious by SimonM's post.
Reply 6
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going_crazy12
OP
Original post by SimonM
Or note that -sin x is the derivative of cos x

thank u simon,
i was using this method but i got stuck after.. :s-smilie: really confused
Reply 7
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nuodai
17
Original post by going_crazy12
thank u simon,
i was using this method but i got stuck after.. :s-smilie: really confused


If you want more help you'll have to show us your working, then we can tell you where you're going wrong or give you a poke in the right direction [but not do the whole thing for you].

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