cosx=(−12)asxin3rdquadrant∴x=π+(π3)=(4π3)
Prove that:
(i) If cos x=−35 and x lies in the IIIrd quadrant, find the values of cos x2, sin x2 and sin 2x.
(ii) If cos x=−35 and x lies in the IInd quadrant, find the values of sin 2x and sin x2