calc
posted by peter .
Give 2 positive and 2 negative angles that are coterminal with each angle?
1. 30 degrees
2. 135 degreed
3. 93 degrees

you can find coterminal angles by adding or subtracting multiples of 360 degrees to any given angle.
e.g. 30 + 360
so 30 and 390 are coterminal
135 + 720 = 755
so 135 and 755 are coterminal.
30  360 = 330
so 30 and 330 are ....etc. 
1. positive 360 and 390
negative 330 and 360
2. positive 135 and 720
negative 330 and 390 
either you misunderstood my examples or you are making arithmetic errors.
think of any angle.
To end up in the same position (coterminal) you would go around once, or twice, or three times...
either in a positive or in a negative direction, wouldn't you?
e.g. your angle of 93 degrees
adding 360 to it gives us 267
now adding another 360 gives us 627
subtraction 360 from 93 gives us 453
and subtracting another 360 yields 813
so 813, 453, 267 , and 627 are all coterminal with 93
taking the sine of each of those will yield the same answer
taking the cosine of each of those will yield the same answer
taking the tangent .....