How do I evaluate a trig function like $\displaystyle sin(4)$ without a calculator? Assuming that, since there is no unit, it's 4 radians...

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- Dec 4th 2012, 07:38 AM #1

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- Dec 4th 2012, 07:46 AM #2

- Dec 6th 2012, 02:02 PM #3

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- Dec 6th 2012, 02:25 PM #4
## Re: Idle curiousity

- Dec 6th 2012, 04:51 PM #5

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## Re: Idle curiousity

Although it is NOT the way trig tables are constructed, the simplest thing to do is to use "MacLaurin" series for sin(x):

$\displaystyle sin(x)= x- \frac{x^3}{3!}+ \frac{x^5}{5!}- \frac{x^7}{7!}+ \cdot\cdot\cdot+ \frac{x^{2n+1}}{(2n+1)!}+ \cdot\cdot\cdot$