determine the exact value of cos 121 degree cos 59 degree-sin 121 degree sin 59 degree
We can simplify the expression using the product-to-sum trigonometric identity:
cos(A - B) = cos(A)cos(B) + sin(A)sin(B)
We have:
cos(121°)cos(59°) - sin(121°)sin(59°)
Using the identity, we can rewrite this as:
cos(121° - 59°)
121° - 59° = 62°
So, the exact value of the expression is cos(62°).