If `alpha=(pi)/(8)`, what is the value of `cosalphacos2alphacos4alpha`?

If alpha=(pi)/(17), then the value of (sin21 alpha-sin alpha)/(sin16 alpha+sin4 alpha) is equal to

If alpha(1+isqrt3)/(2), then what is the value of 1+alpha^(8)+alpha^(16)+alpha^(24)+alpha^(32) ?

" If alpha=(2 pi)/(7) ,then the value of tan alpha tan2 alpha+tan2 alpha tan4 alpha+tan4 alpha tan alpha is "

If alpha=pi/3 , prove that cosalphacos2alphacos3alphacos4alphacos5alphacos6alpha=-1/16

If alpha=pi/3 , prove that cosalphacos2alphacos3alphacos4alphacos5alphacos6alpha=-1/16

If alpha=pi/3 , prove that cosalphacos2alphacos3alphacos4alphacos5alphacos6alpha=-1/16

If alpha=pi/3 , prove that cosalphacos2alphacos3alphacos4alphacos5alphacos6alpha=-1/16

If alpha=(pi)/(31) then find the value of (1)/(4)[(1)/(cos alpha)+(2cos alpha)/(cos2 alpha)+(4cos3 alpha)/(cos4 alpha)+(8cos7 alpha)/(cos8 alpha)]

If alpha=cos ((2pi)/5)+isin((2pi)/5) , then find the value of alpha+alpha^2+alpha^3+alpha^4