Little Trigonometry

For students of class 9-10 (age 14-16)
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Little Trigonometry

Unread post by Rabeeb » Wed Jan 30, 2013 11:42 am

If cos 3=$\sqrt p$,
Then cos 3.cos 6.cos 12$\cdots$cos 384=?
*All angles expressed in degrees

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Nadim Ul Abrar
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Re: Little Trigonometry

Unread post by Nadim Ul Abrar » Wed Jan 30, 2013 12:54 pm

$\displaystyle \cos 3.\cos 6.\cos12 ... \cos 384$ $\displaystyle =\frac{2^7.\sin3.\cos 3.\cos 6.\cos12 ... \cos 384}{2^7.\sin3}=\frac{\sin 768}{2^7.\sin3}=\frac{\sin 48}{2^7.\sin3}$ $\displaystyle =\frac{\sin3+\cos3}{2^7 \sqrt {2}.\sin 3}=\frac{1}{2^7 \sqrt {2}}+\frac{\cot 3}{2^7 \sqrt {2}}$
Last edited by Nadim Ul Abrar on Wed Jan 30, 2013 6:38 pm, edited 2 times in total.

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Re: Little Trigonometry

Unread post by *Mahi* » Wed Jan 30, 2013 1:15 pm

Use \sin, \cos and \tan instead of sin,cos or tan, this way they look more tidy.
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