[" If "(sin alpha)/(a)=(cos alpha)/(b)" then "],[a sin2 alpha+b cos2 alpha=]

I : If (cos alpha )/(a)=(sin alpha )/(b) then a cos 2 alpha + b cos 2 alpha =a II : If (sin alpha )/(a) =(cos alpha )/(b) then a sin 2 alpha + b cos 2 alpha = a

If (sin alpha )/(a) = ( cos alpha )/(b) , then a sin 2alpha + b cos 2 alpha =

If sin alpha + cos alpha = b, then sin 2 alpha is equal to

underset is If tan theta=(sin alpha-cos alpha)/(sin alpha+cos alpha), then sin alpha+cos alpha

IF tan alpha = ( sin alpha - cos alpha )/( sin alpha + cos alpha) , then sin alpha + cos alpha is

If sin alpha + cos alpha = b then sin 2 alpha is equal to . . . . .

(sqrt2 - sin alpha - cos alpha )/( sin alpha - cos alpha)=

(sqrt2 - sin alpha - cos alpha )/( sin alpha - cos alpha)=

Prove that, (cos alpha + sin alpha)/(cos alpha -sin alpha)-(cos alpha - sin alpha)/(cos alpha + sin alpha) = 2 tan 2 alpha