if sin theta 09 find the value of sin theta sin theta2pi s

if sin theta =0.9, find the value of sin theta + sin (theta+2pi) + sin (theta +4pi)

Solution

                sin(theta)+sin(theta+2pi)+sin(theta+4pi)

                 =sin(theta)+sin(theta)+sin(2pi+(2pi+theta))

                = sin(theta)+sin(theta)+sin(2pi+theta)

                 =sin(theta)+sin(theta)+sin(theta)

                 = 3sin(theta)

                 = 3(0.9)

                = 2.7