" (1) "(1-tan^(2)A)/(1+tan^(2)A)=?

If A=30^(@) , then prove that : cos2A=cos^(2)A-sin^(2)A " "=(1-tan^(2)A)/(1+tan^(2)A)

If A=30^(@) , then prove that : cos2A=cos^(2)A-sin^(2)A " "=(1-tan^(2)A)/(1+tan^(2)A)

If /_A=30^(@), verify each of the following (i)sin2A=(tan A)/(1+tan^(2)A)(ii)cos A=(1-tan^(2)A)/(1+tan^(2)A)

Prove that (1-tan^(2)A)/(1+tan^(2)A)=2cos^(2)A-1

sin^(-1)((1-tan^(2)x)/(1+tan^(2)x))

If 3 cot A = 4 , check whether (1-tan^(2)A)/(1+tan^(2)A)=cos^(2)A-sin^(2)A is true or not.

(1) (1-tan^(2)45^(@))/(1+tan^(2)45^(@)) =

sec^(-1)((1+tan^(2)x)/(1-tan^(2)x))

int(1-tan^(2)x)/(1+tan^(2)x)dx