SOLUTION: Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value. cos(30)cos(60)- sin(30)sin(60)

Algebra ->  Trigonometry-basics -> SOLUTION: Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value. cos(30)cos(60)- sin(30)sin(60)      Log On


   

Question 434030: Use an addition or subtraction formula to write the expression as a trigonometric function of one number, and then find its exact value.
cos(30)cos(60)- sin(30)sin(60)
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
cos(30)cos(60)- sin(30)sin(60) = cos(30 + 60) = cos(90) = 0