If `alpha = pi/17`, show that `(cos alpha cos 13alpha)/(cos 3alpha + cos 5 alpha) = -1/2`

If alpha=(pi)/(17), show that (cos alpha cos13 alpha)/(cos3 alpha+cos5 alpha)=-(1)/(2)

If alpha = (pi)/(13), Prove that cos alpha cos 2alpha cos 3alpha cos 4alpha cos 5alpha cos 6alpha = (1)/(64) .

If alpha = pi/3, prove that cos alpha*cos 2alpha*cos 3alpha*cos 4alpha*cos 5alpha*cos 6alpha = -1/16.

If alpha = pi/3 , prove that cos alpha*cos 2alpha*cos 3alpha*cos 4alpha*cos 5alpha*cos 6alpha = -1/16 .

If alpha = pi/3 , prove that cos alpha*cos 2alpha*cos 3alpha*cos 4alpha*cos 5alpha*cos 6alpha = -1/16 .

If 5tan alpha=4, show that (5sin alpha-3cos alpha)/(5sin alpha+2cos alpha)=(1)/(6)

If alpha=(pi)/(23) then the value of (cos10 alpha-cos22 alpha)/(cos10 alpha-cos24 alpha) is equal to

cos alpha*cos60-alpha*cos60+alpha-(1)/(4)cos3 alpha

(cos alpha + 2 cos 3 alpha + cos 5 alpha )/(cos 3 alpha + 2 cos 5 alpha + cos 7 alpha ) = cos 3 alpha sec 5 alpha .

1/(cos alpha + cos 3 alpha)+ 1/(cos alpha + cos 5 alpha)+ 1/(cos alpha + cos 7 alpha) +....+ 1/(cos alpha +cos(2n+1) alpha) = 1/2 "cosec" alpha[tan (n+1) alpha - tan alpha ]