ESSENTIAL MATH help?

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poohead

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ESSENTIAL MATH help?

« on: April 11, 2010, 03:57:51 pm »

hey guys
need help with q23 & 24 of 2b in essentil math

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superflya

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Re: ESSENTIAL MATH help?

« Reply #1 on: April 11, 2010, 04:12:26 pm »

q24)

$\frac{(a_{1})^{2}}{|a|^{2}}+\frac{(a_{2})^{2}}{|a|^{2}}+\frac{(a_{3})^{2}}{|a|^{2}}$

$\frac{(a_{1})^{2}+(a_{2})^{2}+(a_{3})^{2}}{|a|^{2}}$

$|a|^{2}=a\cdot a$

$\Rightarrow \frac{(a_{1})^{2}+(a_{2})^{2}+(a_{3})^{2}}{(a_{1})^{2}+(a_{2})^{2}+(a_{3})^{2}}=1$

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2010- English, Methods (CAS), Physics, Specialist, Chem.
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brightsky

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Re: ESSENTIAL MATH help?

« Reply #2 on: April 11, 2010, 04:13:34 pm »

This should help:

http://en.wikipedia.org/wiki/Direction_cosine

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