If `s e ctheta+t a ntheta=k ,\ costheta=` `(k^2+1)/(2k)` b. `(2k)/(k^2+1)` c. `k/(k^2+1)` d. `k/(k^2-1)`

If s e ctheta+t a ntheta=k ,\ costheta= a. (k^2+1)/(2k) b. (2k)/(k^2+1) c. k/(k^2+1) d. k/(k^2-1)

If sec theta+tan theta=k,cos theta=(k^(2)+1)/(2k)b(2k)/(k^(2)+1)c*(k)/(k^(2)+1)d*(k)/(k^(2)-1)

If t a ntheta_1t a ntheta_2=k , then ("cos"(theta_1-theta_2))/("cos"(theta_1+theta_2))= a. (1+k)/(1-k) b. (1-k)/(1+k) c. (k+1)/(k-1) d. (k-1)/(k+1)

If A+B+C=pi\ &sin(A+C/2)=ksinC/2, t h e ntanA/2tanB/2= a. (k-1)/(k+1) b. (k+1)/(k-1) c. k/(k+1) d. (k+1)/k

If tan theta_(1)tan theta_(2)=k, then (cos(theta_(1)-theta_(2)))/(cos(theta_(1)+theta_(2)))=(1+k)/(1-k) b.(1-k)/(1+k) c.(k+1)/(k-1) d.(k-1)/(k+1)

If (k+(1)/(k))^(2)=16 , then k^(2)+(1)/(k^(2))=

If A+B+C=pi&sin(A+(C)/(2))=k(sin C)/(2), then (tan A)/(2)(tan B)/(2)= a.(k-1)/(k+1) b.(k+1)/(k-1) c.(k)/(k+1) d.(k+1)/(k)

If tantheta_1=kcottheta_2, then find cos(theta_1-theta_2)/cos(theta_1+theta_2)= ................ A) (1+k)/(1-k) B) (1-k)/(1+k) C) (k+1)/(k-1) D) (k-1)/(k+1)

If c is very small when compared to k then ((k)/(k+c))^((1)/(2))+((k)/(k-c))^((1)/(2))=

[(k (k + 1)) / (2)] ^ (2) + (k + 1) ^ (3) = [((k + 1) (k + 2)) / (2) +1] ^ (2)