Question

is cos(a+b) is constant?
elobrate?

Answer 1

yes it is a constant because of the angle i.e., (a+b) a and b are a constant value hence if you'll put any value in the angle you'll get a constant value.

for granted take an example,

put a=45, b=15

cos(45+15)=cos 60= 0.5

again put, a=45 and b=45

cos(45+45)=cos 90=0

I tried to explain,

hopeyou'll understand