Having trouble with these problems can anyone help with any of these questions? And if possible can you explain> been working on this assignment all day and these are the only ones left.
Find the reference angle for the given angle.
Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value.
2. cos (7pie/6) cos (-pie/ 2)-sin(7pie/6)sine(-pie/2)
3. sin (255)
5. cot (135)
6. sin (5pie/6)
Find the exact value