1. ## tan(10pi/3)

isn't tan(10pi/3) supposed to be sqrt(3).. ?

2. Originally Posted by weasley74
isn't tan(10pi/3) supposed to be sqrt(3).. ?
yes

you could have checked that on your calculator, you know

3. Originally Posted by Jhevon
you could have checked that on your calculator, you know
In my mathematics course, no calculators are allowed at all. They're like completely "banned". You may not even multiply or add or do anything similar with it. Might be the same case here. Where you actually have to show all of your steps.

4. yeah, calculators not allowed..

5. Originally Posted by weasley74
isn't tan(10pi/3) supposed to be sqrt(3).. ?
$\displaystyle \frac{10 \pi }{3} = 3 \pi + \frac{ \pi }{3}$

6. no calculators, no problem!

you should know $\displaystyle \tan \frac {\pi}3$ by heart, or know how to get is from the sine and cosine of pi/3

then, by reference angles, $\displaystyle \tan \frac {k \pi}3 = \pm \tan \frac {\pi}3$

the sign depends on what quadrant the angle $\displaystyle \frac {k \pi}3$ is. $\displaystyle \frac {10 \pi}3$ is in the third quadrant, so we take the plus sign