posted by Jillian on .
Calculate the exact values of sin(theta) cos(theta) and tan (theta) when theta=240 degrees.
How would I do this with and without a calculator?
Learn your standard angles in their various orientation around the circle.
0 pi/6 pi/4 pi/3 and pi/2 are important enough to memorize
In degrees, that's 0 30 45 60 90
240 = 180 + 60
so it's in the 3rd quadrant.
Use the functions of 60 degrees, except that sin and cos are both negative there.