# ghshtalt

reputation
2619
bio
website
location
age
member for     2 years, 6 months
seen           Mar 10 at 19:08
profile views  132

check it out

|             |                | bio     | visits   |                 |                   |
|-------------|----------------|---------|----------|-----------------|-------------------|
|             | 842 reputation | website |          | member for      | 2 years, 6 months |
| 2619 badges | location       |         | seen     | Mar 10 at 19:08 |                   |

# 239 Actions

|       |          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|-------|----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Apr17 | comment  | How to show certain things related to scalar products@Theo: yeah that was the 'workaround' I was trying out, but now I can go ahead and replace the alphas thanks to what you just taught me.                                                                                                                                                                                                                                                                                                                                             |
| Apr17 | revised  | How to show certain things related to scalar productsadded 2 characters in body                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Apr17 | comment  | How to show certain things related to scalar products@Theo: thank you so much for that! I was trying to figure out why it was such a mess... definitely valuable remarks!                                                                                                                                                                                                                                                                                                                                                                 |
| Apr17 | revised  | How to show certain things related to scalar productsadded 6 characters in body; added 114 characters in body; added 1 characters in body                                                                                                                                                                                                                                                                                                                                                                                                 |
| Apr17 | asked    | How to show certain things related to scalar products                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Apr17 | comment  | Subtraction and division with integers modulo 3@Gerry: thanks for the explanation. I had copied that notation from Paul R. Halmos -Linear Algebra Problem Book... But, yeah I will definitely try to avoid using those sorts of fractions in the future.                                                                                                                                                                                                                                                                                  |
| Apr17 | accepted | How do you show this property of a differentiable function given information about the derivative?                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Apr17 | comment  | Subtraction and division with integers modulo 3Thank you for this answer                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| Apr17 | comment  | Subtraction and division with integers modulo 3@Fabian: thanks for the helpful tips                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Apr17 | accepted | Subtraction and division with integers modulo 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Apr17 | comment  | Subtraction and division with integers modulo 3@quanta: I'm sorry if I'm just completely missing something here, but are you saying there is a problem with the way I am trying to write down/express an idea, or with the idea itself that I am trying to carry out division on the integers modulo 5?                                                                                                                                                                                                                                   |
| Apr17 | comment  | Subtraction and division with integers modulo 3@quanta: ok, yeah I meant by that 3 divided by 4 in integers modulo 5 (and I realize the way I used $x$ in my above comment was nonsense). But isn't that how you would carry out division of 3 by 4 in integers modulo 5? Since $4$ is the inverse of $4$, $3*4^{-1}=2$ in integers modulo 5, no?                                                                                                                                                                                         |
| Apr17 | comment  | Subtraction and division with integers modulo 3@quanta: thank you for the answer. I'm still digesting it, but I wanted to check if I am understanding part of the idea. If I wanted to divide on say integers modulo 5 (where there are a couple more examples) then for say $\frac{3}{4}=x$ I would first always calculate $4^{-1}$ and then multiply? And because of the gcd stuff you showed, I know that $1\equiv 4x \mod 5 \Rightarrow x = 4 \Rightarrow \frac{3}{4} = 2$? So in these cases it is about finding the inverses first? |
| Apr17 | asked    | Subtraction and division with integers modulo 3                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?@Qiaochu: thanks for that comment, I guess the derivative of a polynomial satisfies $f'(-x)=-f'(x) \Rightarrow f'$ is odd with degree $n \Rightarrow \int f'(x)dx$ is even with degree $n+1$..? Unfortunately I can't say much about a power series or a differentiable function in general...                                                                                                                                          |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?$g(0) = f(0)-f(-0)=0$ ?                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?thank you for this answer. Unfortunately I can't manage to finish the problem with it yet. $g(x) = f(x)-f(-x) \Rightarrow g'(x)=f'(x)+f'(-x) \Rightarrow g'(x) =0 \Rightarrow g(x)=C \Rightarrow ?$ is the rest pretty much as Chris shows, or did you have something else in mind? (The only thing is that I don't know how I would have defined all these other functions and so on...)                                               |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?@Fabian: yeah, careless mistake on my part, thank you for clearing that up                                                                                                                                                                                                                                                                                                                                                              |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?@Fabian: Thank you, I noticed that as well, but wasn't sure if it would turn out to be a 'trick.' As for deducing something: what more than $f(-x) = -f(x)$ or maybe even $f(-x)+f(x)=0$ should I see? Also, why is it ok to evaluate the definite integral here? (sorry if i'm missing very obvious stuff!)                                                                                                                            |
| Apr16 | comment  | How do you show this property of a differentiable function given information about the derivative?@Thomas: It's not homework, but thanks for the hint anyway. If I integrate both sides of the above equation I get $f(-x) + C = -\int f(x)dx$ right? I am not sure what to do with that and in I general get thrown off by the constant whenever I try to use integration...                                                                                                                                                             |
{"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 15, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "github"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "english_confidence": 0.928633451461792, "perplexity_flag": "middle"}