Simplify the expression by using a sum or difference identity cos(86 degrees) cos (26 degrees) + sin(86 degrees) sin(26 degrees)
The sum or difference identity for cosine is:
cos(A - B) = cos(A)cos(B) + sin(A)sin(B)
Using this identity, we can simplify the given expression:
cos(86 degrees) cos(26 degrees) + sin(86 degrees) sin(26 degrees)
= cos(86 degrees - 26 degrees)
= cos(60 degrees)
= 1/2