`(1-tan^2 (theta/2))/(1+tan^2(theta/2))`

If A=[(1,tan(theta/2)),(-tan(theta/2),1)] and AB=I, then B= (A) {cos^2 (theta/2)}A (B) {cos^2(theta/2)}A\' (C) {cos^2(theta/2)}I (D) none of these

If theta=30^@ , verify that: (i) cos2theta=(1-tan^2theta)/(1+tan^2theta) (ii) cos3theta=4cos^3theta-3costheta

simplify (1+tan^(2)theta)+(1+(1)/(tan^(2)theta))

Find the sum n terms of seires tan theta+1/2tan(theta/2 )+1/(2^2)tan(theta/(2^2))+1/(2^3)tan(theta/(2^3))+....

Prove that (tan^2 (2theta)-tan^2 theta)/(1-tan^2 (2theta) tan^2 theta)=tan (3theta)tan theta

Show that (1+tan .theta/2)/(1-tan. theta/2)=(1+sintheta)/(cos theta)=tan(pi/4+theta/2)

Prove that: tan4theta=(4t a ntheta(1-tan^2theta))/(1-6tan^2theta+tan^4theta)

(i) The points (-1, 0), (4, -2) and (cos 2theta, sin 2 theta) are collinear (ii) The points (-1,0), (4, -2) and ((1-tan^(2)theta)/(1+tan^(2)theta),(2tan theta)/(1+tan^(2)theta)) are collinear

Prove that (tan^(2)2theta-tan^(2)theta)/(1-tan^(2)2thetatan^(2)theta)=tan 3 theta tan theta .

If tan theta+tan(60^(@)+theta)+tan(120^(@)+theta)=3, Prove that: (3tantheta-tan^(3)theta)/(1-3tan^(2)theta)=1