[cos^(-1)(cos(13 pi)/(6))" is equat to "],[[" (A) "(pi)/(6),(B)*(7 pi)/(6),(c)(pi)/(3),(D)(13 pi)/(6)]]

cos^(-1)(cos(13pi/6))

cos^(-1)(cos""(13pi)/6)=pi/4 .

Evaluate : cos^(-1)(cos""(13pi)/6)+tan^(-1)(tan""(7pi)/6) .

Prove that: 2cos (pi)/(13) cos (9 pi)/(13)(3 pi)/(13)(5 pi)/(13)=0

The number of solutions of the equation cos^(2) (x + (pi)/( 6)) + cos ^(2) x - 2 cos ( + (pi)/( 6)) co ""(pi)/( 6) = sin ^(2) (pi)/( 6) in interval ((-pi)/( 2), (pi)/( 2)) is _____

Evaluate : "sin" (8 pi)/(3) "cos" (23 pi)/(6) + "cos" (13 pi)/(3) "sin" (35 pi)/(6)