If `tan^2theta=2tan^2phi+1,t h e ncos2theta+sin^2phi` equals (a)`-1` (b) `0` (c) `1` (d) none of these

1 + tan^2 theta = ?

If tan^(-1)(sin^2theta-2sintheta+3)+cot^(-1)(5sin^(2theta)+1)=pi/2, then value of 2cos^2theta-sintheta is equal to 0 (b) -1 (c) 1 (d) none of these

IF tan 2 theta . Tan theta = 1 then theta is

If 3tanthetatanphi=1 , then prove that 2cos(theta+phi) = cos(theta-phi)

The number of roots of (1-tantheta)(1+sin2theta)=1+tanthetafortheta in [0,2pi] is 3 (b) 4 (c) 5 (d) none of these

If sin^2theta=(x^2+y^2+1)/(2x) , then x must be -3 (b) -2 (c) 1 (d) none of these

If y=tan^(-1)((2^x)/(1+2^(2x+1))),t h e n(dy)/(dx)a tx=0 is (a)1 (b) 2 (c) 1n 2 (d) none of these

If sintheta=costheta then 2tan^(2)theta+sin^(2)theta-1=___ .

If sec^4theta+sec^2theta=10+tan^4theta+tan^2theta, then sin^2theta= 2/3 (b) 3/4 (c) 4/5 (d) 5/6

Prove that tan^2 (theta)-sin^2 (theta)= tan^2 (theta) sin^2 (theta)