trigonometry question?

Question

"use the properties of sine and cosine functions to match each value in the column on the left with the column on the right:
1.cos 65 a. cos. 25
2. cos (-25) b. sin (-55)
3. cos 75 c. sin (-75)
4. sin 35 d. sin 25
5. cos (-35) e. sin 15
6. -cos (-15) f. sin 55
7. sin (-25) g. cos 55
8. -sin 55 h. -cos 65

I thought I was doing it right by using this : sin x = cos (90-x), ect...the cofunctions.
for 1 I got D
for 3. I got e.
for 4. I got g.
for 7. I got h.
am I doing something wrong? I tried to do the other ones, but the answers I got didn't have a match on the right side.

Answer 1

cos(x) = sin(90 - x)
sin(x) = cos(90 + x)

1.)
cos(65) = sin(90 - 65) = sin(25)
ANS : D

2.)
cos(-25) = sin(90 - ) = sin(90 + 25) = sin(115) or cos(25)
ANS : A.

3.)
cos(75) = sin(90 - 75) = sin(15)
ANS : E.

4.)
sin(35) = cos(90 + 35) = cos(125) or cos(55)
ANS : G

5.)
cos(-35) = sin(90 - (-35)) = sin(90 + 35) = sin(125) or sin(55)
ANS : F

6.)
-cos(-15) or cos(165) = sin(90 - 165) = sin(-75)
ANS : C.

7.)
sin(-25) = cos(90 + 25) = cos(115) or -cos(65)
ANS : H

8.)
-sin(55) or sin(-55)
ANS : B.
That one was to me tricky, because they didn't need you to convert it to cosine.

sometimes you have to convert them to another degrees so that they match up.

Answer 2

Try graphing them. You are on the right approach. You have to consider qaudrants as well as phase shift.