Is my answer correct?
Question: Find the exact value of the following trig function:

cos (-150deegrees)

answer:
Theta terminates in Quadrant III.
Reference angle is 30degrees
cos = negative in Quadrant III
cos (-150) = -cos (30) = Square root of 3/2

Question

Is my answer correct?
Question: Find the exact value of the following trig function:

cos (-150deegrees)

answer: 
Theta terminates in Quadrant III.
Reference angle is 30degrees
cos = negative in Quadrant III
cos (-150) = -cos (30) = Square root of 3/2

anonymous · Answer

right

anonymous · Answer

Correct

angela210793 · Answer

tht's right

anonymous · Answer

I have a q, If at the end its -cos (30) shouldnt my answer be influenced and become - Square root of 3/2? Or it doesnt matter?

anonymous · Answer

$$\cos (-\theta) = \cos \theta $$

anonymous · Answer

Please dont leave, I have one more question:

anonymous · Answer

to find exact value of tan (225)

is my answer correct?
theta terminates in Q3
R. angle is 45
tan = positive in Q3
tan(225) = tan(45) = 1

experimentx · Answer

tan(180+45)

experimentx · Answer

whenever there is 180 turn function remains same, and or 90 function changes.

angela210793 · Answer

i wish u knew albanian -_- i'd have explained these to u -_-

anonymous · Answer

Wait, so 1 is wrong?

anonymous · Answer

so exact balue of tan(225) is not 1?

anonymous · Answer

*value

anonymous · Answer

1 is right!

anonymous · Answer

Oh. lol. Ok thank you guys so much! as usual you guys ROCK!!:)