`cos^2A-sin^2A=(1-tan^2A)/(1+tan^2A)`

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)

If A= 30^@ verify that :- cos2A= (1-tan^2A)/(1+tan^2A) .

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)

Show that cos 2 x=cos ^(2) x-sin ^(2) x=2 cos ^(2) x-1=1-2 sin ^(2) x=(1-tan ^(2) x)/(1+tan ^(2) x)

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

If cos^(2)A-sin^(2)A=tan^(2)B then prove that 2cos^(2)B-1=tan^(2)A

If A=30^(@), prove that sin2A=2sin A cos A=(2tan A)/(1+tan^(2)A)

(cos2A) / (1-sin2A) = (1 + tan A) / (1-tan A)