Sin2A & Cos2A Formulae

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

Prove that (1 + sin2A) / (cos2A) = (cos A + sin A) / (cos A-sin A)

Representation of sin2A;tan2A and cos2A in terms of tan A with proof.

(1 + sin2A) / (cos2A) = (cos A + sin A) / (cos A-sin A) = tan ((pi) / (4) +1)

Evaluate sin2A, cos2A and tan2A if: i) sinA=5/13 , ii) cosA=8/17 , iii) tanA=4/3

if sin2A=2sin A cos A and sin20^(@)=K then the value of cos20^(@)cos40^(@)cos80^(@)cos160^(@)-

Prove that formula cos(A-B)=cos A*cos B+sin A*sin Bwith the help of the formula sin(A+B)=sin A*cos B+cos A*sin B

(sin2A) / (sin A) - (cos2A) / (cos A) = sec A

Using the formula, sinA=sqrt((1-cos2A)/(2)) , find the value of sin30^(@) , it being given that cos60^(@)=(1)/(2) .