The Unit Circle

EASY PRACTICE PROBLEMS!

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Solve using the Unit Circle provided(answers at bottom of page):

Ex.      cos 90°=0    why? Because the x-coordinate at 90° is 0!

Ex.      sin45°=√2 /2       why? Because the y-coordinate at 45° is √2 /2!


1) cos 180°=?

2) cos 270°=?

                                                                                          3) sin 210°=?

                                                                                            4) sin 45°=?









Answers:

1)-1

2)0

3)-1/2

4) √2 /2