19h accepted Use $\sin^22t=4\sin^2t(1-\sin^2 t)$ to show that $\sin t$ is not a polynomial? 1d asked About the convenient rewriting of formulas of sequences? 1d asked Use $\sin^22t=4\sin^2t(1-\sin^2 t)$ to show that $\sin t$ is not a polynomial? Aug11 asked Where can I read about the techniques for computing areas and volumes before calculus? Aug10 asked Is the area of a convex polygon equal to the area of a circle with the same perimeter of the polygon? Aug3 awarded Notable Question Jul21 comment Prove the reflexivity of $\subseteq$. @GitGud Yes, but what you mean with "eliminating the universal quantifier"? Is there a process to do it or I just need to throw it away? Jul21 comment Prove the reflexivity of $\subseteq$. @GitGud I don't really know. I've imagined some things but none of them is nice. I remember of the "getting hid of $\forall x$", I've heard a small piece about it in a lecture but I had to leave and didn't get the rest. Jul21 comment Prove the reflexivity of $\subseteq$. @GitGud Excuse me. But what's the difference of $\forall$ and "take an arbitrary $x$"? Jul21 asked Prove the reflexivity of $\subseteq$. Jul20 revised Is there something that studies equivalent forms of writing and expression? edited body Jul20 comment Is there something that studies equivalent forms of writing and expression? @JHance Yes, thanks. Jul20 asked Is there something that studies equivalent forms of writing and expression? Jul16 revised How to turn arbitrary fractions into arbitrary egyptian fractions? edited title Jul16 asked How to turn arbitrary fractions into arbitrary egyptian fractions? Jul16 comment What do we lose by differentiating without using the rules of differential calculus? Good point you made in your first sentence. There are rules that are more primitive and these can be used to derive the others, right? Jul13 asked What do we lose by differentiating without using the rules of differential calculus? Jul12 comment Differentiating $\frac{te^{\tan t}}{ln(3t+1)}$? Excuse me, you wrote "$f_2'\cdot f_1'$ is trivial", shouldn't it be $f_2\cdot f_1'$? Jul12 asked Curiosity about Kronecker's Delta? Jul12 accepted Differentiating $\frac{te^{\tan t}}{ln(3t+1)}$?