Javier
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 Jul 21 comment Compute integral $\int_{-6}^6 \! \frac{(4e^{2x} + 2)^2}{e^{2x}} \, \mathrm{d} x$ After doing the change of variables, shouldn't it be $u^2$ instead of $e^{2u}$ in the numerator? Jul 21 comment Motivation for definition of logarithm in Feynman's Lectures on Physics I just saw in the feynmanlectures.info site that this has been added to the errata. Awesome! Jul 20 comment Find all solutions, other than $2$ for $12x^3-23x^2-3x+2=0$ @Austin: You don't need to ask. You could just plug in those values and check whether they satisfy your equation. Jul 19 comment Help solving differential equation: $y' = x\sqrt{4+y^{2}}/{y(9+x^{2})}$ The right side of the equality can be written as $\frac{\sqrt{4+y^2}}{y} \frac{x}{(9+x^2)}$. Does this help? Jul 16 accepted Motivation for definition of logarithm in Feynman's Lectures on Physics Jul 15 comment Motivation for definition of logarithm in Feynman's Lectures on Physics I get it now, thank you! This paragraph is really weird, considering that the rest of the lectures is very well written and clear. Jul 15 comment Motivation for definition of logarithm in Feynman's Lectures on Physics @joriki: That really helps. Thanks! Jul 15 asked Motivation for definition of logarithm in Feynman's Lectures on Physics Jul 15 comment Is the function $y=\ln x^2$ the same as $y=2\ln |x|$? Short answer: yes. Jul 14 revised Problems regarding exponents Not smart to use the same letters as in the assignments Jul 14 comment Problems regarding exponents @Rick: Yeah, I think I'll change it. Thanks for the advice! Jul 14 answered Problems regarding exponents Jul 7 comment I have to show $(1+\frac1n)^n$ is monotonically increasing sequence Unless I'm missing something, that sequence is increasing, not decreasing. Jul 1 accepted Does this weird sequence have a limit? Jun 30 comment Does this weird sequence have a limit? That's interesting. Does this change if instead of picking a number from ${1,2,3,4,5,6}$ we choose a random real number, or maybe one from the interval $[0,1]$? Jun 30 comment Does this weird sequence have a limit? @anon: Making a needlessly complicated definition was sort of the point. Also, you don't necessarily have to choose $k$ randomly. You can start from $1$ and work your way up if you want; the point is not so much in what order the terms are calculated, but that you can calculate $a_k$ for any $k$ you want. Jun 30 comment Does this weird sequence have a limit? @AndréNicolas: What I mean if that $a_k$ has already been calculated, there is no need to roll the die again. We just look at the list and check what was the value of $a_k$. Jun 30 asked Does this weird sequence have a limit? Jun 24 awarded Nice Question Jun 23 revised Expanding out summation signs transformed image into latex, hope I read it right