SOLUTION: Evaluate the expression under the given conditions. cos(theta-psi); cos(theta)= 5/13, theta in Quadrant IV, tan(psi) = -sqrt(3), psi in Quadrant II

Algebra ->  Trigonometry-basics -> SOLUTION: Evaluate the expression under the given conditions. cos(theta-psi); cos(theta)= 5/13, theta in Quadrant IV, tan(psi) = -sqrt(3), psi in Quadrant II      Log On


   

Question 1155615: Evaluate the expression under the given conditions.
cos(theta-psi); cos(theta)= 5/13, theta in Quadrant IV, tan(psi) = -sqrt(3), psi in Quadrant II
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!


cos(theta)=5/13 in quadrant IV --> sin(theta) = -12/13.

tan(psi) = -sqrt(3) in quadrant II --> sin(psi) = sqrt(3)/2, cos(psi) = -1/2.

cos(A-B) = cos(A)*cos(B)+sin(A)*sin(B)

Plug in the numbers and do the calculation.