Do you need the answer as a decimal or a fraction?
Answer:
C
Step-by-step explanation:
The difference formula for cosine is
cos(x - y) = cosxcosy + sinxsiny
Consider
cos75 = cos(120 - 45)°, then
cos(120 - 45)°
= cos120°cos45° + sin120°sin45° → C
Answer:
19-12=7, so 4-7=-3, so b is equal to 19