I have no idea what to do. Our professor didnt teach us this. help please.

Find the value of

if

is in the second quadrant and

Draw a triangle in the second quadrant and label the sides . You will get a negative value for cos .

Find the value of

if

is in the third quadrant and

Same thing . Draw a triangle in the 3rd quadrant . Sin a will be negative .

Find the value of

if

and

Given cos a is negative and sin a is postitive . Thus the angle will be in the 2nd quadrant . Draw a triangle in the second quadrant .

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