If `|2sintheta-cos e ctheta|geq1a n dtheta!=(npi)/2,n in Z ,` then `cos2thetageq1/2` (b) `cos2thetageq1/4` `cos2thetalt=1/2` (d) `cos2thetalt=1/4`

Prove that : (2 cos 2^n theta + 1)/(2 cos theta +1) = (2 cos theta -1) (2 cos 2theta -1) (2 cos 2^2 theta -1) … (2 cos 2^(n-1) theta -1)

Solve 2cos^2theta+sinthetalt=2, where pi/2lt=thetalt=(3pi)/2dot

(sin3theta)/(2cos2theta+1)=(1)/(2) if (n in Z)

If sintheta(1+sin^(2)theta)=cos^(2)theta , then prove that cos^(6)theta-4cos^(2)theta+8cos^(2)theta=4

Prove that (1+costheta+isintheta)^(n)+(1+costheta-isintheta)^(n)=2^(n+1)cos^(n)((theta)/(2))cos((ntheta)/(2))

If cot^3alpha+cot^2alpha+cotalpha=1 then (a) cos2alpha.tanalpha=-1 (b) cos2alpha.tanalpha=1 (c) cos2alpha-tan2alpha=1 (d) cos2alpha-tan2alpha=-1

If (cos theta)/(1+sintheta)=(1)/(a) then prove that (a^(2)-1)/(a^(2)+1)=sintheta .

zo is one of the roots of the equation z^n cos theta0+ z^(n-1) cos theta2 +. . . . . . + z cos theta(n-1) + cos theta(n) = 2, where theta in R , then (A) |z0| 1/2 (C) |z0| = 1/2

If cos e ctheta-cottheta=q , then the value of cos e ctheta is (a) q=1/q (b) q-1/q 1/2(q+1/q) (d0 none of these

Iflambda=int_0^(pi/2)costhetaf(sintheta+cos^2theta)dtheta a n dI_2=int_0^(pi//2)sin2thetaf(sintheta+cos^2theta)dtheta,t h e n I_1=-2I_2 (b) I_1=I_2 2I_1=I_2 (d) I_1=-I_2