Quispiam
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 Sep13 asked $\sin 4\alpha = 2\sin 2\alpha \times \cos 2\alpha$? Sep13 asked Two unrelated equations, $w^2 = -\frac{15}{4} - 2i$ and $z^2 - (3-4i)z + (2-4i) = 0$? Sep12 comment Calculate $\cos(v+\frac{\pi}{6})$ when $\cos v = -\frac{2}{3}$ This helped a lot, I found the answer and it seems to be correct ($-\frac{2\sqrt{3}+\sqrt{5}}{6}$). Thank you! Sep12 accepted Calculate $\cos(v+\frac{\pi}{6})$ when $\cos v = -\frac{2}{3}$ Sep12 asked Calculate $\cos(v+\frac{\pi}{6})$ when $\cos v = -\frac{2}{3}$ Sep10 accepted Finding highest possible value of function Sep10 revised Finding highest possible value of function p(t), not t Sep10 asked Finding highest possible value of function Sep4 accepted Calculating the chess problem, sum $\sum_{k=0}^{63}2^{k}$ Aug30 comment Calculating the chess problem, sum $\sum_{k=0}^{63}2^{k}$ Discovered my mistake - it was supposed to be $2^{64} - 1$, not $2^{64} + 1$. Aug30 asked Calculating the chess problem, sum $\sum_{k=0}^{63}2^{k}$ Aug29 accepted Calculate absolute values with unknown constant Aug26 asked Calculate absolute values with unknown constant Aug25 comment Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$ It seems I figured everything out now. It was part of a bigger problem (uniting it with another inequality) and it seems like everything goes together perfectly now. Thanks a lot for the help. Aug25 comment Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$ Sorry, that was me being too excited after suddenly getting things right for once. Should have kept checking for roots after finding the obvious one. Thank you. Aug25 comment Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$ Thank you! Calculating for case (2) I find the root $-1$ for $2x^2 - 43x - 45$. Adding this to the roots of $2x(x+\frac{3}{2})$, this should mean that the entire expression is negative when $\frac{-3}{2} \lt x \lt -1$ or $0 \lt x$. However, when testing higher numbers (approximately where $x \gt 22$), $2x^2 - 43x - 45$ becomes positive and so the entire expression becomes positive. Why is this? Aug25 awarded Commentator Aug25 comment Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$ Thank you. Correction, though - the $45$ should be negative. Aug25 accepted Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$ Aug25 asked Finding all $x$ for $\frac{2x - 13}{2x + 3} \lt \frac{15}{x}$