State the signs of `cos (frac(-8pi)(3))^2`

Find the trignometric functions of (frac(2pi)(3))^c

Select the correct option from the given alternatives: cos^-1(cos(frac{7pi}{6})) = ..... A) frac{7pi}{6} B) frac{5pi}{6} C) frac{pi}{6} D) frac{3pi}{2}

Prove the following: (frac(cos(pi+x)cos(pi-x))(sin(pi-x)cos(pi/2+x)))=cot^2x

The expression cos ((10pi)/13)+cos ((8pi)/13)+cos ((3pi)/13)+cos ((5pi)/13) is equal to............... A) -1 B) 0 C) 1 D) None of these

Prove the following: (frac(sin3x)(cosx))+(frac(cos3x)(sinx))=2cot2x

frac{8!}{2(6!)}

Prove the following: cos^-1(frac{3}{5})+cos^-1(frac{4}{5}) = frac{pi}{2}

Prove the following: (1+cos (pi/8))(1+cos((3pi)/8))(1+cos ((5pi)/8))(1+cos ((7pi)/8))=1/8

Find the polar co-ordiantes of point whose cartesian co-ordinates are: (frac{3}{2},frac{3sqrt3}{2})

If omega_n = cos(frac{2pi}{n})+sin(frac{2pi}{n}) , i^2 = -1 , then (x+y(omega_3)+z(omega_3)^2)(x+y(omega_3)^2+z(omega_3)) is equal to