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(ƒÎ/6) = cos(ƒÎ/3) = 1/2
cos(ƒÎ/6) = sin(ƒÎ/3) = ã3/2
tan(ƒÎ/3) = ã3
tan(ƒÎ/6) = 1/ã3
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 alt251 for squareroot, which probably works for Microsoft Word, but not for this forum which requires HTML codes.
For π, type in
& p i ;
(without the spaces inbetween) and for
squareroot, use
& r a d i c ;