Recent content by niall14

thanks, but how did i show it is a sphere, i can work out it is unit speed?

can somebody give a solution to wat the image of x(u,v)=(cos u*cos v,cos U*sin v, sin u) is? where x:U ->R^3 u,v is an element of R^2 such that -pi/2 < u < pi/2, -pi < v < pi help appreciated greatly thank you

thanks ill give it a go

thanks for your reply.not really to sure what u mean by 'project'.if you could give me the first few lines of the proof I am sure i could figure it out.

In cartesian coordinates (x.y,z) on the and (X,Y) on the plane, the projection and its inverse are given by the following formulae: (X,Y)=(x/1-z,y/1-z) (x,y,z)=(2X/1+X^2+Y^2, 2Y/1+X^2+Y^2, -1+X^2+Y^2/1+X^2 +Y^2) This relates to the field of differential geo.Anybody have a proof to where thes...