# tan(10pi/3)

• February 12th 2008, 12:55 PM
weasley74
tan(10pi/3)
isn't tan(10pi/3) supposed to be sqrt(3).. ?
• February 12th 2008, 12:58 PM
Jhevon
Quote:

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 :D
• February 12th 2008, 01:03 PM
janvdl
Quote:

Originally Posted by Jhevon
you could have checked that on your calculator, you know :D

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.
• February 12th 2008, 01:07 PM
weasley74
yeah, calculators not allowed..
• February 12th 2008, 01:09 PM
janvdl
Quote:

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

$\frac{10 \pi }{3} = 3 \pi + \frac{ \pi }{3}$
• February 12th 2008, 01:12 PM
Jhevon
no calculators, no problem!

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

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

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