If `(cos^4x)/(cos^2y)+(sin^4x)/(sin^2y)=1,"show taht", (cos^4y)/(cos^2x)+(sin^4y)/(sin^2x)=1`

If (cos^(4)x)/(cos^(2)y)+(sin^(4)x)/(sin^(2)y)=1 , then (cos^(4)y)/(cos^(2)x)+(sin^(4)y)/(sin^(2)y) equal :

If cos^4x/cos^2y+sin^4x/sin^2y=1 ,show that cos^4y/cos^2x+sin^4y/sin^2x=1

If cos^4x/cos^2y+sin^4x/sin^2y=1 ,show that cos^4y/cos^2x+sin^4y/sin^2x=1

Show that 3(sin^4x+cos^4x)-2(sin^6x+cos^6x)=1 .

If (cos ^ (4) x) / (cos ^ (2) y) + (sin ^ (4) x) / (sin ^ (2) y) = 1 then prove that (cos ^ (4) y) / (cos ^ (2) x) + (sin ^ (4) y) / (sin ^ (2) x) = 1

If (cos x)/(cos y)=a and (sin x)/(sin y)=b, then (a ^(2)-b^(2))*sin^(2)y =......

If sin^(2)x+cos^(2)y=1 , show that dy/dx=(sin2x)/(sin 2y)

If cos x+ cos y = 1//3 , sin x + sin y=1//4 " then " cos (x+y)=

If sin y=x sin(a+y), then show that: (dy)/(dx)=(sin a)/(1-2x cos a+x^(2))

(cos x- cos y) ^(2) + (sin x - sin y) ^(2) =4 sin ^(2) "" ( x-y)/(2)