" 19.If "a=(cos theta+i sin theta)," prove that "(1+a)/(1-a)=(cot(theta)/(2))i

If a=cos theta+i sin theta, then (1+a)/(1-a) is equal to ( i) cot((theta)/(2))( ii) cot theta( iii) i cot((theta)/(2))( iv )i tan((theta)/(2))

If a=cos theta+i sin theta, then (1+a)/(1-a)=(cot theta)/(2) b.cot theta c.i(cot theta)/(2)d*i(tan theta)/(2)

Prove that (1+cos theta)/(sin theta)=cot[(theta)/(2)]

If alpha=cos theta+i sin theta, then (1+alpha)/(1-alpha) equals ( (i)cot theta(ii)i tan((theta)/(2))(iii)i cot((theta)/(2))(iv)cot((theta)/(2))

Prove that : (1-cos theta+i sin theta)/(1+i sin theta+cos theta)=ie^(-1)tan((theta)/(2))

Prove that sin(2theta)/(1-cos2theta)=cot theta

Prove that: (sin2 theta)/(1-cos2 theta)=cot theta

Prove each of the following identities : (1+ cos theta - sin^(2) theta)/(sin theta (1+ cos theta)) = cot theta

Prove that (tan theta+ sin theta)/(tan theta-sin theta)= (sec theta+1)/(sec theta-1) OR Prove that (cosec theta- cot theta)^(2)=(1-cos theta)/(1+cos theta)

Prove each of the following identities : (i) (1+ cos theta + sin theta)/(1+ cos theta - sin theta) =(1+ sin theta)/(cos theta) (ii) (sin theta + 1- cos theta)/(cos theta - 1 + sin theta) = (1+ sin theta)/(cos theta)