SOLUTION: Use a sum or difference formula to find the exact value of the following. {{{ sin(13pi/15)cos(7pi/60)-cos(13pi/15)sin(7pi/60) }}} =

Algebra ->  Trigonometry-basics -> SOLUTION: Use a sum or difference formula to find the exact value of the following. {{{ sin(13pi/15)cos(7pi/60)-cos(13pi/15)sin(7pi/60) }}} =       Log On


   

Question 985940: Use a sum or difference formula to find the exact value of the following.
+sin%2813pi%2F15%29cos%287pi%2F60%29-cos%2813pi%2F15%29sin%287pi%2F60%29+ =
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
sin%2813pi%2F15%29%2Acos%287pi%2F60%29+-+cos%2813pi%2F15%29%2Asin%287pi%2F60%29 = sin%28%2813pi%2F15%29%2B%287pi%2F60%29%29 = sin%2859pi%2F60%29 = sin%28pi%2F60%29 = sin(3°).

                                                                        %2813pi%2F15%29%2B%287pi%2F60%29 = %28%2813%2A4%2B7%29%2Api%29%2F60 = 59pi%2F60