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

If alpha = cos((8pi)/11)+i sin ((8pi)/11) then Re(alpha + alpha^2+alpha^3+alpha^4+alpha^5) is

If alpha = cos((8pi)/11)+i sin ((8pi)/11) then Re(alpha + alpha^2+alpha^3+alpha^4+alpha^5) is

If alpha=(pi)/(7), then find the value of ((1)/(cos alpha)+(2cos alpha)/(cos2 alpha))

If alpha=(pi)/(7) then find the value of ((1)/(cos alpha)+(2cos alpha)/(cos2 alpha))

If alpha=cos((8 pi)/(11))+i sin((8 pi)/(11)) then Re(alpha+alpha^(2)+alpha^(3)+alpha^(4)+alpha^(5)) is

If alpha=cos((8pi)/11+isin((8pi)/11 then Re(alpha+alpha^2+alpha^3+alpha^4+alpha^5) is

If alpha=cos((2pi)/7)+i sin((2pi)/7) then a quadratic equation whose roots are (alpha+ alpha^(2)+ alpha^(4)) and (alpha^(3)+ alpha^(5)+alpha^(6))

If alpha_r=(cos2rpi+isin2rpi)^(1/10) , then |(alpha_1, alpha_2, alpha_4),(alpha_2, alpha_3, alpha_5),(alpha_3, alpha_4, alpha_6)|= (A) alpha_5 (B) alpha_7 (C) 0 (D) none of these

If alpha_r=(cos2rpi+isin2rpi)^(1/10) , then |(alpha_1, alpha_2, alpha_4),(alpha_2, alpha_3, alpha_5),(alpha_3, alpha_4, alpha_6)|= (A) alpha_5 (B) alpha_7 (C) 0 (D) none of these