Which trigonometric ratios are negative for the angles: `(-(5pi)/6)^c`

Which trigonometric ratios are negative for the angles: 315^@

Which trigonometric ratios are negative for the angles: -210^@

Which trigonometric ratios are positive for the following angles (i) 210^@ (ii) -135^@ (iii) ((2pi)/3)^c

If A+B+C=pi, express S=sin3A+sin3B+sin3C as a product of three trigonometric ratios. If S=0, Show that at least one of the angles is 60^@.

Find all other trigonometrical ratios if sintheta=-(2sqrt(6))/5 andtheta lies in quadrant III.

Express sin 67^@+cos 75^@ in terms of trigonometric ratios of angles between 0^@ and 45^@ .

Given tanA=4/3 , find the other trigonometric ratios of the angle A.

Express cot 85^o +cos75^o in terms of trigonometric ratios of angles between 0^o and 45^o

Express cos70^(@)+sin70^(@)+tan65^(@) in terms of trigonometric ratios of angles lying between 0^(@)and45^(@)

Find the values of the following trigonometric ratio: tan ((11pi)/6)