If `a=pi/18` rad,then `cos a +cos 2a+........+18a` is equal to

If a=(pi)/(18) rad,then cos a+cos2a+......+18a is equal to

IF a = (pi)/( 18) radius then cos a + cos 2 a + …. + cos 18 a =

cos 72^@ - sin18^@ is equal to

Statement-I If alpha=(pi)/(18) then cos alpha+ cos 2 alpha+..... +cos18 alpha=0 Statement- II If (a+2) sin theta(2a-1) cos theta=2a+1 then tan theta=(4)/(3) Which of the above statements is correct

If alpha =(pi)/(18) radian then the value of (cos alpha + cos 2 alpha+ cos 3 alpha +…+ cos 18 alpha) is-

If the expression cos(x-3(pi)/(2))+sin(3(pi)/(2)+x)+sin(32 pi+x)-18cos(19 pi-x)+cos(56 pi+x)-sin(x+17 pi) is expressed in the form of a sin x+b cos x, then a+b is equal to

If the expression cos(x - 3pi/2) + sin(3pi/2+x) + sin(32pi+x) - 18 cos(19pi-x)+cos(56pi+x) - 9sin(x+17pi) is expressed in the form of a sinx + bcos x , then a+b is equal to

The value of 4 cos 18^(@)-(3)/(cos 18^(@))-2 tan 18^(@) is equal to

The value of 4 cos 18^(@)-(3)/(cos 18^(@))-2 tan 18^(@) is equal to