Question

Prove+that+sina+sin2a+sin3a+sin4a/cosa+cos2a+cos3a+cos4a=tan5a/2

Answer 1

Step-by-step explanation:

(sin4A+sinA)+(sin3A+sin2A)

/ (cos4A+cosA)+(cos3A+cos2A)

={2sin5A/2cos3A/2+2sin5A/2cosA/2{2cos5A/2cos3A/2+2cos5A/2cosA/2}

=2sin(5A/2){cos3A/2+cosA/2)/ 2cos5A/2{cos3A/2+cosA/2}

=sin(5A/2)/cos(5A/2)

=tan5A/2