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 Dec 2 comment (approximately) compute absolute largest eigenvalue of symmetrix 3x3 matrix @PVAL defined "many". Definitely many more than 20. Dec 2 comment (approximately) compute absolute largest eigenvalue of symmetrix 3x3 matrix I'm only interested in $3\times3$ matrices (as stated). Solving for all 3 eigenvalues can be done using the exact formula for the roots of a 3rd order polynomial, but does call $\arccos$ once and $\cos$ twice, which are computationally expensive. Dec 2 revised (approximately) compute absolute largest eigenvalue of symmetrix 3x3 matrix specified the meaning of "many" Dec 2 asked (approximately) compute absolute largest eigenvalue of symmetrix 3x3 matrix Mar 15 comment Evaluate the line integral of $\frac{1}{z-a}$ over $\gamma$, where $\gamma=a+Re^{it}$, $0\leq t\leq 2\pi$ and a is a complex number A proof was not asked for ... Mar 14 comment Pi Day question This is all wrong any way, as it's not 3/14/15: it makes not sense (in this mathematical context) to list month/day/year/hour. You have to be consistent and order the sub-units. Then we get 2015/03/15/09.26.53 etc. Mar 14 revised If $\tan\alpha,\, \tan\beta,\,\tan\gamma$ are roots of $au^ 3 +(2a-x)u+ y=0$ use $\tan$ instead of $tan$ Mar 14 suggested approved edit on If $\tan\alpha,\, \tan\beta,\,\tan\gamma$ are roots of $au^ 3 +(2a-x)u+ y=0$ Mar 14 comment Evaluate the line integral of $\frac{1}{z-a}$ over $\gamma$, where $\gamma=a+Re^{it}$, $0\leq t\leq 2\pi$ and a is a complex number Hint? answer! Mar 14 comment Finding extrema of function of two unit vectors @Demosthene yes, of course. so what? Mar 14 comment Finding extrema of function of two unit vectors @Demosthene $\hat{\boldsymbol{x}}$ is one of the function arguments and not a constant unit vector. Mar 14 asked Finding extrema of function of two unit vectors Sep 30 awarded Scholar Sep 30 accepted General solution to first-order ODE in 3D Sep 29 comment General solution to first-order ODE in 3D thanks. So I learned about the matrix exponential. Great! (I would accept this comment morphed into an answer ...) Sep 28 asked General solution to first-order ODE in 3D Sep 24 awarded Autobiographer Sep 3 comment Analyze rotation of satellite orbit due to transverse acceleration. I've answered this question here. Jun 29 comment integral of spherical harmonics over cube I wanted to know the multipole moments of constant density cube. So knowing which vanish is only part of the story. I also need the value for those which don't. Preferrably not the numerical value, but a closed formula. Feb 4 comment Wanted: simple invertible function with specified derivative properties @copper.hat Sorry, that fails: $F''(0)\neq0$.