cos^(2)A(tan^(2)A+1)=1

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 that (i) sin2A=(2tanA)/(1+tan^(2)A) (ii) cos2A=(1-tan^(2)A)/(1+tan^(2)A) (iii) tan2A=(2tanA)/(1-tan^(2)A)

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

2cos^(2)B-1=tan^(2)A, then cos A cos B

2cos^(2)B-1=tan^(2)A, then cos A cos B=

Prove that (tan^(2)A-1)/(tan^(4)A-1)=cos^(2)A

Prove: (cos^2 A + tan^2 A -1)/(sin^2 A ) = 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-cos2A)/(1+cos2A)=tan^(2)A