Ben Alpert
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 Jun23 comment Use of “inverse” to mean reciprocal Yes, I understood that the reciprocal is a type of inverse, but "inverse" seems overly general to specify a reciprocal relationship. Jun23 asked Use of “inverse” to mean reciprocal Jun22 comment Finding $\sin(4a)$ if we know $\cos a$ Please ask your second problem as an entirely new question instead of as an edit to this one. Jun21 comment Proving Stewart's theorem without trig Thanks, your answer is definitely good enough for my purposes. Good night! Jun21 comment Proving Stewart's theorem without trig Very nice, thanks! Jun21 accepted Proving Stewart's theorem without trig Jun21 asked Proving Stewart's theorem without trig May26 awarded Nice Answer May15 comment Function $F$ that $F(x)+F(-x)=\lim_{y\rightarrow\infty}F(y), \forall x \in \mathbb{R}$ @Tim: Might want to change the title too. May10 comment Calculate intersection of 2 points @J.M. I'm pretty sure Ross Millikan interpreted it right. You have two points and two slopes given as angles from the vertical ($\pi/2$) and want the intersection between the two lines thus determined. May4 revised How to accurately calculate the error function erf(x) with a computer? fix broken link! May4 suggested approved edit on How to accurately calculate the error function erf(x) with a computer? Apr28 comment Why the name 'FACTORIAL'? But that's true of other numbers (both smaller and larger) that aren't the factorial. Apr27 revised How to solve this recurrence relation? (convolution integral) edited tags Apr27 revised When is a recurrence relation linear edited tags Apr27 revised There is a table of the complexity of recursive algoritms? edited tags Apr26 comment Calculating the highest possible damage achievable using 6 items from a pool of ~25 Probably belongs on SO. Apr25 comment Inclusion-exclusion principle: Number of integer solutions to equations @DAK: Reread Gerry's last paragraph. For the intersection of $A_1$ and $A_2$, it's equivalent to solving $v_1+v_2+y_3+y_4=5$ with $v_1, v_2, y_3, y_4 \ge 0$. Just like the number of solutions to solve $y_1+y_2+y_3+y_4 = 12$ is $C(15,3)$, the number of solutions to that equation (and the size of the $\lvert A_1 \cap A_2 \rvert$ set) is $C(8,3)$. Apr25 comment Inclusion-exclusion principle: Number of integer solutions to equations I agree, I think it's $C(12 + 4 - 1, 3) = C(15,3)$. Apr16 awarded Nice Question