Question

What is tan 5pi/6?

Answer 1

can't you use a calculator?

Answer 2

nope no calculator

Answer 3

tan(x)=tan(x-pi), and tan(-x)=-tan(x).
+ use tan(pi/6)=\(\frac{\sqrt3}{3}\)

Answer 4

so -sqrt3?

Answer 5

no.
tan(5pi/6) = tan(-pi/6) = ...

Answer 6

-18.8496?

Answer 7

It is really helpful to get the unit circle with trig function values in your head.

Answer 8

With that in mind, I'd do it this way:
We know that tan 5pi/6 = [sin (5pi/6)]/[cos(5pi/6)]
Then using the lovely unit circle in my head, I get that
[sin (5pi/6)]/[cos(5pi/6)] = (1/2) / (-sqrt(3)/2) = -2/2sqrt(3)

Answer 9

The answers I have are
-sqrt 3
-1/sqrt3
-1
1/sqrt3

Answer 10

Great. Then you're good to go...unless u have questions regarding the working out..

Answer 11

which one is the answer for it?

Answer 12

Simplify the solution I gave.

Answer 13

soo 1/sqrt3?

Answer 14

Hmm...what happened to the -ve sign?

Answer 15

oooh ok -1/sqrt3

Answer 16

Yes. And definitely commit the trig unit circle to memory.