Re: Vector problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg115959] Re: Vector problem*From*: m.perrin at me.com*Date*: Thu, 27 Jan 2011 03:41:50 -0500 (EST)

The Mathematica part of the problem was that Projection could be included in the Solve function. I wasn't aware that Solve could take that input Solve [ {Projection[ {x,y} , v ] == v, Projection[ {x,y} , u ] == u}, {x,y}] (* where {x,y} is unknown vector z, and u and v are the known 2D vectors ; spaces are for clarity*) But as I posted, I solved the problem (no pun intended). On Jan 26, 2011, at 05:07 AM, Murray Eisenberg <murray at math.umass.edu> wrote: This doesn't at all sound like a Mathematica problem, but rather like a mathematics problem. On 1/25/2011 4:19 AM, Mark Perrin wrote: > I'm having trouble formulating a problem in Mathematica. > > If I have two 2D vectors, u and v that are the known projections of a third unknown 2D vector z, how do I determine z? > > My word problem (I think) is find the solution to: Projection[z,u] == u&& Projection [z,v] == v > > Any help in starting this problem would be much appreciated. > >