Question

Cos ( A + 45°) + Sin (A -45°) = ________​

Answer 1

Answer:

x=-21

Step-by-step explanation:

cos245o−cos230o=x.cos45o.sin45o

∴(21)2−(23)2=x(21)(21)

∴21−43=2x

∴42−3=2x

∴−41=2x

∴x=−21