What is this expression as the cosine of an angle cos30cos55 plus sin30sin55?

cos(30)cos(55)+sin(30)sin(55)=cos(30-55) = cos(-25)=cos(25)

Note: cos(a)=cos(-a) for any angle 'a'.

cos(a)cos(b)+sin(a)sin(b)=cos(a-b) for any 'a' and 'b'.