Problems
Problem :
Express the following as a sum or difference:
sin(56)cos(42)
.
sin(56)cos(42) =
(sin(56 + 42) + sin(56 - 42)) =
(sin(98) + sin(14))
.
Problem :
Express the following as a sum or difference:
cos(115)cos(60)
.
cos(115)cos(60) =
(cos(115 + 60) + cos(115 - 60)) =
(cos(175) + cos(55))
.