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Jonas Meyer earned this badge 6 times
nov 25 at 12:49Is a square matrix whose diagonal and antidiagonal elements are all zero always singular?
may 9 '11 at 1:18Derivation of the formula for the vertex of a Parabola
may 7 '11 at 1:32Upper-triangular matrix is invertible iff its diagonal is invertible: C*-algebra case
dec 11 '10 at 18:23Measure of the Cantor set plus the Cantor set
nov 9 '10 at 18:53(post deleted or otherwise unavailable)
nov 1 '10 at 10:40Intuitive understanding of the derivatives of $\sin x$ and $\cos x$