cos^(-1)(-(1)/(2))" Find the main value of. "

Find the principal value of "cos"^(-1)(-1/(2)) and find the value of "cos"^(-1)(-1/(2))+"tan"^(-1)(-sqrt(3))-"cosec"^(-1)(2) .

Find the value of "cos"22 1/2@

Find the value of cos^-1(-1)

Find the values of cos22""1_(@)/2

Find the principal value of cos^-1(-1/2)

Find the principal values of cos^(-1)(1/2)

Find the principal value of cos^(-1)(-1/2)

Find the values of cos(67""1/2)^(@)

Find the value of cos[22(1/2)]^o

Find the value of cos^-1(-1//2) .