Question

sqrt(1-x^2) + sqrt(1-y^2) = a(x-y)
prove that dy/dx = sqrt[ (1-y^2)/(1-x^2) ]

Answer 1

put \[x=\sin \theta \] and \[y=\sin \phi \]....

Answer 2

then we get \[\frac{\cos \theta + \cos \alpha }{ \sin \theta - \sin \alpha } = a\]
then after that what to do next

Answer 3

well...use this
\[\cos \theta + \cos \alpha =2 \cos(\theta+\alpha )/2*\cos(\theta -\alpha )/2\]
and \[\sin \theta -\sin \alpha= 2\cos(\theta+\alpha )/2*\sin(\theta-\alpha )/2\]

Answer 4

do you know this formulas...?

Answer 5

yes very much and thanks a lot

Answer 6

got your answers?