most recent 30 from http://mathoverflow.net 2013-05-21T14:46:20Z http://mathoverflow.net/feeds/user/44 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/83/how-to-approximate-a-solution-to-a-matrix-equation FarmBoy 2009-10-03T18:01:06Z 2010-01-18T22:49:32Z

<p>Suppose a matrix equation <code>Ax = b</code> has no solution (<code>b</code> is not in the column space of <code>A</code>)</p> <p>How can I find a vector <code>x'</code> so that <code>Ax'</code> is the closest possible vector to <code>b</code>?</p>

http://mathoverflow.net/questions/72/whats-an-example-of-a-function-whose-taylor-series-converges-to-the-wrong-thing FarmBoy 2009-10-02T16:51:31Z 2009-11-29T19:28:56Z

<p>Can anyone provide an example of a real-valued function <em>f</em> with a convergent Taylor series that converges to a function that is not equal to <em>f</em> (not even locally)?</p>

http://mathoverflow.net/questions/81/when-does-a-matrix-equation-have-a-solution FarmBoy 2009-10-03T14:28:55Z 2009-10-03T18:55:24Z

<p>Given a matrix equation <code>Ax = b</code> where <code>A</code> is a matrix and <code>b</code> is a column vector, what is a condition that would ensure that there is a column vector <code>x</code> that satisfies the equation?</p> <p>Assume the dimensions are sensible, and feel free to provide multiple conditions.</p>