If `A-[[sin((3 pi)/(2)),sin pi,2],[cos((2 pi)/(3)),1,k],[cos pi,-4,tan((pi)/(4))]]` is a singular matrix, then the value of k is

If [[sin((pi)/(2)), cos((pi)/(3))], [2tan((pi)/(4)), 2k]] is not invertible, then k=

sin(pi/4+A).sin(pi/4-A)=1/2 cos2A

sin pi/3 = 2sin pi/6 cos pi/6

sin ^ (2) ((2 pi) / (3)) + cos ^ (2) ((5 pi) / (6)) - tan ^ (2) ((3 pi) / (4))

sin (pi/2) = 2 sin(pi/4) cos (pi/4)

sin ^ (2) ((pi) / (6)) + cos ^ (2) ((pi) / (3)) - tan ^ (2) ((pi) / (4)) = - (1) / (2)

If [(cos (2pi)/7,-sin (2pi)/7),(sin (2pi)/7,cos (2pi)/7)]^k=[(1,0),(0,1)], then the least positive integral value of k, is

let cos((pi)/(7)),cos((3 pi)/(7)),cos((5 pi)/(7)), the roots of equation 8x^(3)-4x^(2)-4x+1=0 then the value of sin((pi)/(14)),sin((3 pi)/(14)),sin((5 pi)/(14))

Find the value of the sin^(2)((pi)/(6))+cos^(2)((pi)/(3))-tan^(2)((pi)/(4))