f cos theta=(1)/(2)(x+(1)/(x))," then "(1)/(2)(x^(2)+(1)/(x^(2)))=

If x=sqrt((1- cos theta )/(1+ cos theta )), " then " (2 x)/(1-x^(2))=

If sec theta+tan theta=x, then sec theta=(a)(x^(2)+1)/(x) (b) (x^(2)+1)/(2x)(c)(x^(2)-1)/(2x) (d) (x^(2)-1)/(x)

If costheta=1/2(x+1/x) then 1/2(x^2+1/x^2) =............. A) sin 2 theta B) cos 2 theta C) tan 2 theta D) sec 2 theta

i) Prove that: (1-sin2A)/(1+sin2A) = tan^(2)(pi/4-A) ii) If costheta=1/2(x+1/x) , then prove that: cos2theta=1/2(x^(2)+1/x^(2)) and cos3theta=1/2(x^(3)+1/x^(3))

i) Prove that: (1-sin2A)/(1+sin2A) = tan^(2)(pi/4-A) ii) If costheta=1/2(x+1/x) , then prove that: cos2theta=1/2(x^(2)+1/x^(2)) and cos3theta=1/2(x^(3)+1/x^(3))

If 2 cos theta=x+1/x then prove that cos 2 theta=1/2 (x^(2)+1/x^(2))

If 2cos theta=x+1/x then 2cos^2 theta=

If sec theta+tan theta=x, then tan theta=(x^(2)+1)/(x) (b) (x^(2)-1)/(x)( c) (x^(2)+1)/(2x) (d) (x^(2)-1)/(2x)

If x=sqrt((1-cos theta)/(1+cos theta)), then (2 x)/(1-x^(2))=