urgent

substituting..............

u'll get.........

(1-sin²u)^1/2+(1-sin²v)^1/2=a(sinu-sinv)

cosu+cosv=a(sinu-sinv).......

a=cosu+cosv/sinu-sinv

a=(2.cos(u+v)/2.cos(u-v)/2)/(2.cos(u+v)/2.sin(u-v)/2)

=cot((u-v)/2)

we can write.......

u-v/2=cot^-1a........

sin^-1x-sin^-1y=cot^-1a

Differentiating.........

1/(1-x²)^1/2=1/(1-y²)^1/2dy/dx

dy/dx=(1-y²)^1/2/(1-x²)^1/2

Got it!!!!!!!!