 # Ben Grossmann

United States

(Formerly Omnomnomnom). I received my PhD in mathematics at Drexel University in Philadelphia, PA in 2019. My primary research area is matrix analysis.

• An explanation of two's complements
• Explaining the transcendental numbers
• A quick linear algebra chestnut
• A trick I keep reusing
• Guide to matrix norms
• Norm minimizing solutions
• What is homology/cohomology ("for dummies" explanation)
• What is knot theory (another "for dummies" explanation)

### Some of my favorite questions/answers:

• $$\int_{-1}^1\frac1x\sqrt{\frac{1+x}{1-x}}\ln\left(\frac{2\,x^2+2\,x+1}{2\,x^2-2\,x+1}\right)\ \mathrm dx$$; a feat of mathematical wizardry
• A classic result from different approaches
• Apparent patterns that eventually fail
• Bad math that gets away with it; great for a few good laughs
• Some great math puzzles

• Non-symmetric PD matrices, https://math.stackexchange.com/a/188334/81360
• MathJax tutorial and quick-reference
• How to ask a good question
• MSE Blog
Top Questions

## Prove that if $A$ is normal, then eigenvectors corresponding to distinct eigenvalues are necessarily orthogonal (alternative proof)

asked May 2, 2014 at 22:13

## How was the first log table put together?

asked Sep 5, 2013 at 17:07

## Prove that if positive-definite $f$ is continuous at $0$, it is continuous on $\mathbb{R}$

asked Nov 17, 2013 at 6:23