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In[1]:= Simplify[x<0, x<0] Out[1]= True In[2]:= Simplify[x<0, {x,y}<0] Out[2]= x < 0 In[3]:= $ Version Out[3]= 11.1.0 for Linux x86 (64-bit) (March 13, 2017) I always thought {x,y}<0 meant the same thing as {x<0, y<0}, but, per In[2] above, this doesn’t appear to be the case. Does {x,y}<0 have a useful meaning or am IRead more

How we can remove all pairs {x,y} of a list which begin from a special x. For example: list={{1,2},{4,5},{5,9},{8,13},{9,0.1},{15,-0.2},{17,-9},{23,2}}; We want keep pairs in which x=<9: extractlist={{1,2},{4,5},{5,9},{8,13},{9,0.1}};Read more

There are $ n$ points randomly by uniform distribution distributed in the plane. We know that no two points have the same $ (x ,y)$ . What is the probability that a point has one of these properties? it has maximum value of $ x$ and maximum value of $ y$ among $ n$ points.Read more

I would like to plot the $ (x,y)$ phase diagram under this constraint: $ $ -\frac{x}{3} – \sqrt{\left( \frac{x}{3} \right)^2 – \frac{y}{6}} = 0$ $ I tried to use ContourPlot ContourPlot[-x/(3) – Sqrt[(x/(3))^2 – y/(6)], {x, -10, 10}, {y, -10, 10}] The problem that I am not sure how to interpret the plot. Why don’tRead more