The value of `4 cos(pi/10)-3 sec(pi/10)- 2 tan(pi/10)`is equal to

The value of 2(tan pi)/(10)+3(sec pi)/(10)-4(cos pi)/(10) is 0 b.1 c.sqrt(5)d .none of these

The value of cos^(-1){1/sqrt2(cos((9pi)/10)-sin((9pi)/10))}

The value of (cos(pi/10)+isin(pi/10))(cos((2pi)/10)+isin((2pi)/10))(cos((3pi)/10)+isin((3pi)/10))(cos((4pi)/10)+isin((4pi)/10)) is

The numerical value of tan(pi/3)+2tan((2pi)/3)+4tan((4pi)/3) is equal to

The value of cos((pi)/(10))cos((2 pi)/(10))cos((4 pi)/(10))cos((8 pi)/(10))cos((16 pi)/(10))

The value of 32cot^(2) (pi/4)-8sec^(2)(pi/3)+ 8cos^(3)(pi/6) is equal to

The value of cos(pi/2^2).cos(pi/2^3)……….cos(pi/2^10).sin(pi/2^10) is

The principal value of cos^(-1) {1/sqrt2 ("cos"(9pi)/10 - "sin"(9pi)/10)} is :