Question

Express as product of trigonometric ratios:- sin105 Degree +cos15 degree

Answer 1

sin(105)+cos(15)
=sin(105)+sin(90-15)
=sin(105)+sin(75)
=2*sin((105+75)/2)*cos((105-75)/2)
=2*sin(90)*cos(15)
=2cos(15)
Property used: sinA+sinB=2sin((A+B)/2)cos((A-B)/2)