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 May 28 awarded Popular Question Apr 16 revised How do you evaluate $f(x_n)$? added 87 characters in body Apr 16 revised How do you evaluate $f(x_n)$? edited body Apr 16 answered How do you evaluate $f(x_n)$? Apr 15 comment Proof by contradiction and order of statements @Amateur yep. I take it back. Apr 15 comment Proof by contradiction and order of statements @Amateur I'm not sure that it's correct to say that $\mathbb{R}$ is a closed interval, although you're certainly right that it's a closed set. Apr 15 comment Proof by contradiction and order of statements For your last note, just make a truth table and check. Apr 15 comment applications of derivatives : maxima and minima Do you have any thoughts on this? What would it mean if the derivative of a function at a point was $10100$? What would the function look like at that point? Why couldn't that be a maximum? Apr 15 comment Problem with trigonometric equation That problem looks pretty tough to solve analytically to me. Where did you come across it? Apr 15 comment Question about the Continuum Hypothesis The answer to "where did I go wrong" is that OP took "Clearly this is either true or false - there either exists such a set, or there does not exist such a set" to be true, and this demonstrates that that's not so obvious. Apr 15 answered Question about the Continuum Hypothesis Apr 14 reviewed Approve Autocorrelation and spectral density in MATLAB Apr 14 comment If $x^2 +xy =10$ then when $x=2$ what is $\frac{\mathrm dy}{\mathrm dx}$? do you mean "when $x=2$"? Apr 14 answered Let $n\ge 2$ be an integer. If $\gcd(a,b^n)=1$, then $\gcd(a,b)=1$ Apr 14 reviewed Approve Linear Algebra nullSpace and multiplication Apr 14 comment Probability Equation That I am missing here "Don't ask me why but I just logically see that it is 50% so why?" That's a dangerous way to think about math. Apr 13 answered Every n × n-matrix A with real entries has at least one real eigenvalue. Apr 13 comment Writing Series as a Telescoping Series yes, I was mistaken, sorry :(. I realized immediately and deleted my comment. Apr 13 comment Proof by induction valid or not? @DavidK I know. But either way, it is never correct to assume that the formula works for all $n$. Apr 13 comment Writing Series as a Telescoping Series That's not $S_N$. It's $t_N$ where $S_N=\sum_{i=9}^N t_N$.