`c(1+cos2theta)=` (A) `c 2sin^2theta` (B) `c2cos^2theta` (C) `c2tan^2theta` (D) none of these

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

The value of (cos3theta)/(2cos2theta-1) is equal to (a) costheta (b) sintheta (c) tantheta (d) none of these

The value of (cos3theta)/(2cos2theta-1) is equal to (a) costheta (b) sintheta (c) tantheta (d) none of these

The value of cos^4theta+sin^4theta-6cos^2theta is (a) cos2theta (b) sin2theta (c) cos4theta (d) none of these

If [(1,-tantheta),(tantheta,1)][(1,tantheta),(-tantheta,1)]^(-1)=[(a,-b),(b, a)] , then a=1,\ \ b=0 (b) a=cos2\ theta,\ \ b=sin2\ theta (c) a=sin2\ theta,\ \ b=cos2theta (d) none of these

a sin^(2) theta + b cos^(2) theta =c implies tan^(2) theta =

By using above basic addition/ subtraction formulae, prove that (i) tan (A+B)=(tan A+tan B)/(1-tan A tan B) , (ii) tan (A-B)=(tan A-tanB)/(1+tan A tan B) (iii) sin2theta=2sintheta costheta , (iv) cos2theta=cos^(2)theta=1-2sin^(2)theta=2cos^(2)theta-1 (v) tan 2theta=(2 tan theta)/(1-tan^(2) theta)

(1+sin 2theta+cos 2theta)/(1+sin2 theta-cos 2 theta) =

If sintheta+sin^2theta=1 , then cos^2theta+cos^4theta= (a) -1 (b) 1 (c) 0 (d) None of these

The value of t a nthetasin(pi/2+theta)cos(pi/2-theta) is -1 b. 1 c. 1/2sin2theta d. none of these