Posted by Matt on .
give exact value of cos 75 degrees.
give exact value sin 15 degrees.
give exact value sin 225 degrees.
You will have to use the addition relations here. Notice 75 is 30 +45, 15 is 4530, and 225 is 180 + 45.
I will be happy to critique your work.

trig 
Anonymous,
how would you find csc^2 of 42 degrees then?