Prove that
cos
(
30
°
-
A
)
cos
(
30
°
+
A
)
+
cos
(
45
°
-
A
)
cos
(
45
°
+
A
)
=
cos
2
A
+
1
/
4
.
Matching exercise
Match the items on the right to the items on the left.
Check
OK
STEP 1
STEP 2
STEP 3
STEP 4
