If `P_n=cos^ntheta+sin^ntheta` and `Q_n=cos^ntheta-sin^ntheta`, then which of the following is/are true.

cosm theta - sin ntheta =0

cos mtheta + cos ntheta=0

If sintheta+cosectheta=2 then sin^ntheta+cosec^ntheta=

If S_n=cos^ntheta+sin^n theta then find teh value of 3S_4-2S_6

If costheta + sectheta = (-2) then cos^ntheta + sec^ntheta = (If n is even)

If x=cos e ctheta-sintheta and y=cos e c^ntheta-sin^ntheta, then show that (x^2+4)((dy)/(dx))^2=n^2(y^2+4)dot

If x=cos e ctheta-sintheta and y=cosec^ntheta-sin^ntheta, then show that (x^2+4)((dy)/(dx))^2=n^2(y^2+4)dot

If P_n=cos^ntheta+sin^ntheta, show that : 2P_6-3P_4+1=0 .

If p_n =cos^n theta+sin ^ntheta then the value of 2P_6-3P_4+1 will be