Aug
16
comment Is $a \circ b = \sqrt{a^2+b^2}$ ever a group?
do you mean that there is an inverse if $a,b \in \mathbb{C}$ (instead of $a,b \in \mathbb{Z}$) ?
Aug
16
comment Determining if a recursively defined sequence converges and finding its limit
I added a prove of the convergence to my answer
Aug
15
comment Determining if a recursively defined sequence converges and finding its limit
I see now. It is not proven by the OP.
Aug
15
comment Determining if a recursively defined sequence converges and finding its limit
@Did Thank's. This necessary assumption is already proved in the OP. The question was "So, if this limit exists, how do I actually find it?"
Aug
15
comment Rouche's Theorem Polynomial
-1 for posting a picture instead of a text. Already discussed here math.stackexchange.com/questions/891709/…
Aug
15
comment Rouche's Theorem Polynomial
it is necessary to show that there is no zero in $\{z: |z|=\frac{3}{2}\}$
Aug
14
comment Placing symbols so that no row remains empty.
6! is to large because you have two symbols twice.
Aug
12
comment Diophantine inequality that comes up after Vieta Jumping Hurwitz technique
not quotation marks, but semicolon. On my Windows notebook I can use the Alt Numpad input method to produce "ö" bei pressing directly "[Alt]+148". [Alt] is the left Alt-key, 148 must be typed on the numeric keypad. This works in comments, too. These codes work for me: en.wikipedia.org/wiki/Code_page_437#Characters
Aug
12
comment Diophantine inequality that comes up after Vieta Jumping Hurwitz technique
One can use the html technic: "ö" is written as "ö" or "ö". This works in questions and answers but not in comments. de.selfhtml.org/html/referenz/zeichen.htm#benannte_iso8859_1
Aug
12
comment Archimedes' Apprxomation of Square Roots
the second sequence does not give only lower bounds. Starting with $x_1=x_2=\frac{5}{3}$ one gets: "lower bound","lower bound","upper bound","lower bound","lower bound","upper bound",...
Aug
11
comment Prove that $f(a) \leq f(x) \leq f(b) $
There is something missing: $f'(x) ≥ ?$
Aug
11
comment What's the probability of third coin being of 50 cent?
You can put the mouse pointer over a formatted text ( like $x^2+y^2$ ) and select "Show Math As -> TeX Commands" from the context menue (right mouse button) to get the TeX source of of an expression.
Aug
10
comment Solve the equation $(x^2-9)+\sqrt{2-x}=0$
Your "5." is right. But I don't see any sense in splitting $(x^2-9)$ to $(x+3)(x-3)$. Such unnecessary calculations can give rise to calculation errors that simlply can be avoided by avoiding such calculations.
Aug
10
comment Sequential Algebraic Problem:
I don't like the upload of pictures instead of text. Pictures are not searchable, text of pictures cannot be copied and pasted, the size of the font cannot be changed. Pictures can be removed from the server. Your picture does not bring any additional infomation So why do you not post text? meta.math.stackexchange.com/questions/1805/…
Aug
10
comment $\left | -(x+2)^2+6(x+2) \right |>13$
related to math.stackexchange.com/questions/892613/…
Aug
10
comment Break Even Point
Your costs per $x$-thousand units is $C(x)$ thousand dollars so the costs per unit are $\frac{C(x)}{1000x}$ thousand dollars. This are $1000 \frac{C(x)}{1000x}$ dollars. This is equal to $\frac{C(x)}{x}$ dollars per unit. The price per unit is $p(x)$ dollars.
Aug
9
comment Sequential Algebraic Problem:
-1 for posting a picture of the text
Aug
9
comment Probability problem from FELLER'S book
@Jorge Fernández: My vote on this answer is locked until it is edited. Otherwise I would revoke my downvote due to the comment of André Nicolas.
Aug
9
comment Probability problem from FELLER'S book
@André Nicolas: Thank you for the explanation. Now I understand. This is a very instructive example.
Aug
9
comment Probability problem from FELLER'S book
-1 I don't understand your argumentation. But your numbers contradict the numbers of @André Nicolas, who is right.