" 20.The value of "cos^(2)((pi)/(6)+x)-sin^(2)((pi)/(6)-x)" is "

Find the value of cos^(2)((pi)/(6) - (theta)/(2)) - sin^(2) ((pi)/(6)+(theta)/(2)) .

cos^(2)(""(pi)/(6) + theta ) -sin^(2)""((pi)/(6) - theta ) =

The value of 2sin^(2)((pi)/(3))-cos^(2)((pi)/(6))+tan^(2)(pi/6) is equal to ....

The value of 2"sin"^(2)(pi)/(6)+"cosec"^(2)(7pi)/(6)."cos"^(2)(pi)/(3) is equal to

The value of cos y cos ((pi)/(2) - x) - cos ((pi)/(2) - y) cos x + sin y cos ((pi)/(2) - x) + cos x sin ((pi)/(2) - y) is zero if

One of the value of ("cos"(pi)/(6) +i "sin"(pi)/(6))^((1)/(2)) + ("cos"(pi)/(6)- i "sin"(pi)/(6))^((11)/(2)) is

cos^2(pi/6+theta)-sin^2(pi/6-theta)=

One of the values of ((cos (pi)/(6)-i sin (pi)/(6))^(1 / 2))((cos (pi)/(6)+i sin (pi)/(6))^(1 / 2)) is

The value of sin^(6)((pi)/(49))+cos^(6)((pi)/(49))-1+3sin^(2)((pi)/(49))cos^(2)((pi)/(49)) is equal to