Posted by **jenny** on Wednesday, August 24, 2011 at 4:31pm.

Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of si -pi/6, cos 5/3pi and tan 4pi/3.

I have found the answers to the first three using the special tables

sin(/6) = cos(/3) = 1/2

cos(/6) = sin(/3) = 3/2

tan(/3) = 3

tan(/6) = 1/3

I know that the symmetry of sin(-pi/6 is in the third quadrant, so 7pi/6 =

- 0.5

the symmetry of cos 5pi/3 i have taken 2pi - 5pi/3 to give cos pi/3 = 0.5 but i am not too sure where the symmetry comes in

With the tan I do not quite know where to start. Maybe pi + pi/3.

As for plotting the graphs of sin,cos and tan; I do not know where to start here using the pi radians (whereas as usually I am good at plotting graphs. (perhaps it is an age thing :-(

- math -
**bobpursley**, Wednesday, August 24, 2011 at 5:34pm
Your symbols baffle me. Sorry.

- math -
**jenny**, Wednesday, August 24, 2011 at 6:47pm
what symbols

- math -
**MathMate**, Wednesday, August 24, 2011 at 7:06pm
You have been using alt-251 for square-root, which probably works for Microsoft Word, but not for this forum which requires HTML codes.

For π, type in

& p i ;

(without the spaces in-between) and for

square-root, use

& r a d i c ;

## Answer This Question

## Related Questions

- math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...
- math - use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I ...
- math - use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I have...
- MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...
- Trig - Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < ...
- Trigonometry desperate help, clueless girl here - 2. solve cos 2x-3sin x cos 2x...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- precalculus - For each of the following determine whether or not it is an ...
- Math- Trig - 1. Determine the exact value of cos^-1 (pi/2). Give number and ...
- Trigonometry - Please review and tell me if i did something wrong. Find the ...

More Related Questions