SOLUTION: Hello there! My homework asks another question and asks me to find: a)tan 60 degrees b)sin 225 degrees c)cos 270 degrees I used the unit circle to help me, however t

Algebra ->  Trigonometry-basics -> SOLUTION: Hello there! My homework asks another question and asks me to find: a)tan 60 degrees b)sin 225 degrees c)cos 270 degrees I used the unit circle to help me, however t      Log On


   

Question 880328: Hello there!
My homework asks another question and asks me to find:
a)tan 60 degrees
b)sin 225 degrees
c)cos 270 degrees
I used the unit circle to help me, however the graphs on my homework all show with an arrow that I need to go counter clockwise to find the answer. Thank you for your help, I am getting better with the Unit Circle work, just still a little confused. VERY appreciated! :)
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Use how the angles are related to reference angles from the first quadrant. This is the general way of using the Unit Circle.

(b) sin(225), find how this relates to 90 or 180 or 360 degrees and use positions on unit circle to be sure of signs. 180%3C225%3C270; your arrow is pointed into the third quadrant. 225-180=45 degree difference. This points in the complete opposite direction from 45 degrees of the first quadrant. The sign of the sine is NEGATIVE.
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sin%28225%29=-sin%2845%29=-sqrt%282%29%2F2.

(c) cos(270), this is between quadrant 3 and 4.
180%3C270%3C360 and 3%2A90=270, completely vertical pointing downward. y=-1 and x=0.
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cos%28270%29=0.