formula to evaluate tangent of thrice of an angle

\[\frac{sinA+sin 2A+sin4A+sin5A}{cosA+cos2A+cos4A+cos5A}=tan3A \]

For A=20

\[LHS =\frac{sin20+sin 2*20+sin4*20+sin5*20}{cos20+cos40+cos80+cos100}=1.73205 radian \]

\[RHS=tan 3*20=tan60=1.732 radian \]

Posted on by
Score
Views