Prove that `cot(A/2)=(sin A)/(1-cos A)`

Prove that ( sin 2 A )/( 1 - cos 2 A) = cot A

Prove that : (1 + cos A)/(1 - cos A) = (cosec A + cot A)^(2)

Prove that : (sin A)/ (1 + cos A) + (1 + cos A)/ (sin A) = 2 cosec A

If three angles A, B, and C are in A.P. prove that: cot B=(sin A-sin C)/(cos C-cos A)

If in Delta ABC , angle C = 90 ^(@) , prove that : sqrt((1-sin A)/(1+cos B))= sec A -cot B

Prove that: (a) (sin 2 theta)/(1+cos 2 theta)=tan theta (b) (1+sin 2 theta+cos 2theta)/(1+sin2 theta-cos 2 theta)=cot theta

Prove that : (1)/ (sin A - cos A) - (1)/ (sin A + cos A) = (2 cos A)/(2 sin^(2) A - 1)

Prove that: (sin9A-sin7A)/(cos7A-cos9A)=cot8A

Prove that: (sin9A-sin7A)/(cos7A-cos9A) = cot8A

Prove that: (cos A+cos B)/(cos B-cos A)=cot((A+B)/2)cot((A-B)/2)