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#1 2009-02-25 16:03:15
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Help Mme plzz in this trigonometric problem
prove that:(1-tan²θ)/(1+tan²θ)=2cos²θ-1?
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#2 2009-02-25 17:01:22
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Re: Help Mme plzz in this trigonometric problem
-- Boozer
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#3 2009-02-26 06:06:54
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Re: Help Mme plzz in this trigonometric problem
MAny THx u really saved me
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#4 2009-02-26 11:13:50
- LampShade
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Re: Help Mme plzz in this trigonometric problem
I bit of advice for these... Always take the more complicated side. It's easier to simplify something than it is to complify it. Also, look to see where you're going. If you're going from tan to cos, use whatever identities you can to convert your tan into sin and cos. Example... tan x = sin x / cos x, or tan² x = sec² x - 1, which is what I did above. One last thing, since the right hand side had two terms and no fractions, that gave me a hint as to breaking apart my fraction into two terms. Always use where you want to go as a road map. And you're very welcome 
-- Boozer
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