Why is there no on/off button for irons? I've never seen any iron have an on/off button. So my guess is that most of them do not have one. Is there any specific reason for that?
Why don't sandwich toasters have an on/off switch? The absolute majority of electrical appliances have an On/Off switch. However, the absolute majority of sandwich toasters do not - you just plug them into the socket and unplug them when you're done. At least, that's the case for all household sandwich toasters I've ever seen. I'm referring to this device, not the vertical toaster (where the lever doubles as a switch):    It looks like some models do have a switch, but apparently these are just the larger/industrial types, not the common variety.  Why is that?
Can I read the hash portion of the URL on my server-side application (PHP, Ruby, Python, etc.)? Clip for each feature I want to clip a polyline feature class by a polygon feature class (buffers created from points). Several polygons overlap, so I want to get each polygon feature clipped with each polyline feature.  Using the Clip_analysis tool, I get the orange lines:   whereas I want the following red lines:    In a python script, I tried the following code to clip every polyline with each polygon:          temp = arcpy.ValidateTableName("clip_temp")     bufferCursor = arcpy.SearchCursor(buffer)     n = 0     for pRow in bufferCursor:         arcpy.AddMessage(n)         feat = pRow.Shape         arcpy.Clip_analysis(inputPolylineLayer, feat, temp, "#")         if n == 0:             arcpy.Copy_management(temp, clip)         else:             arcpy.Append_management(temp, clip)         n=n+1   But the execution is very very slow and it crashes before finishing.  I also tried the Intersect_analysis tool but I didn't get the right geometries:   Do you have any idea of a better methods to do it? A question about the arctangent addition formula. In the arctangent formula, we have that:  $$\arctan{u}+\arctan{v}=\arctan\left(\frac{u+v}{1-uv}\right)$$  however, only for $uv&lt;1$. My question is: where does this condition come from? The situation is obvious for $uv=1$, but why the inequality?  One of the possibilities I considered was as following: the arctangent addition formula is derived from the formula:  $$\tan\left(\alpha+\beta\right)=\frac{\tan{\alpha}+\tan{\beta}}{1-\tan{\alpha}\tan{\beta}}.$$  Hence, if we put $u=\tan{\alpha}$ and $v=\tan{\beta}$ (which we do in order to obtain the arctangent addition formula from the one above), the condition that $uv&lt;1$ would mean $\tan\alpha\tan\beta&lt;1$, which, in turn, would imply (thought I am NOT sure about this), that $-\pi/2&lt;\alpha+\beta&lt;\pi/2$, i.e. that we have to stay in the same period of tangent.  However, even if the above were true, I still do not see why we have to stay in the same period of tangent for the formula for $\tan(\alpha+\beta)$ to hold. I would be thankful for a thorough explanation. From the third week ( when does it actually begin) This describes a certain natural process that takes 15 weeks  It describes what a certain component looks like at some point in time during a naturallly occurring process  What I don't get is if it means it appears this way starting in the third week or after ?  Here's the full sentence  "The malleus first appears as a cartilage model from the third week"  Thanks again for you support guys How to trigger workflow from button in O365 I created a script editor webpart. I added a button which start a js function in the onClick event. I would like to start a workflow which is implemented on some list. Is this possible? Does scikit-learn have forward selection/stepwise regression algorithm? I'm working on the problem with too many features and training my models takes way too long. I implemented forward selection algorithm to choose features.  However, I was wondering does scikit-learn have forward selection/stepwise regression algorithm? The pigeonhole principle - how to solve questions like that? We have two sequences , $(a_i)_{i=1}^{2n}$ and $(b_i)_{i=1}^{2n}$ such that  $1\leq a_i, b_i\leq n$ for every $i$.  Show that there are two sets of indexes $I, J \subseteq \left \{ 1,2, ... 2n \right \}$ such what $\sum_{i\in I}a_i=\sum_{j\in J}b_j$.  Well, the question didn't say anything about those sets being empty but I believe that's not what they meant. I don't know that to do with questions like these. There are obviously much more subsets that possible sums ($2^{2n}-1$ compared to $2n^2$) but it doesn't really help.  I'd be glad to hear ideas, hints or solutions. How to take the gradient of the quadratic form? It's stated that the gradient of:  $$\frac{1}{2}x^TAx - b^Tx +c$$  is   $$\frac{1}{2}A^Tx + \frac{1}{2}Ax - b$$  How do you grind out this equation? Or specifically, how do you get from $x^TAx$ to $A^Tx + Ax$? How can I get the page numbers only of a pattern in a pdf file, regardless if the pattern is multiline? Finding the inverse of the arc length function I'm writing a tool to report information about .NET applications deployed across environments and regions within my client's systems.  I'd like to read the values of assembly attributes in these assemblies.  This can be achieved using Assembly.ReflectionOnlyLoad, however even this approach keeps the assembly loaded.  The issue here is that I cannot load two assemblies that have the same name from different paths, so naturally I can't compare the same application deployed in different systems.  At this point I'm assuming the solution will involve using temporary AppDomains.  Can someone detail how to load an assembly into another AppDomain, read the attributes from it and then unload the AppDomain?  This needs to work for assemblies on the file system as well as those at URL addresses. How do I theme the Nautilus background image? I want to change the background image in the Nautilus file browser. My idea is to put my own style in the background. I'm using Ubuntu 11.10 and Nautilus is version 3.  I know that I have to change the nautilus.css file of the theme, but the problem is that there is not a parameter for the background. I just want to apply an image but I can't find the file or parameter to change it.  The CSS file is in the directory /home/UserName/.theme/MyTheme/gtk-3.0/apps. I've changed the nautilus.css file. I wrote two new lines using CSS style but I don't know where the correct place is to put it. The lines are:   background-image: url("carbon.jpg"); background-repeat: repeat;   Obviously I put the image called carbon.jpg in the same directory of nautilus.css, but this change doesn't work because I need to know whichs class displays the Nautilus file browsing frame. If I find this class I guess that this code will work.  If someone knows how to do it, please tell me because I really want to make this change. SEO repeated keywords in domain and url I believe this to be fraud — hired, then asked to cash check and send cash as Bitcoin I have been "hired" by Nissan Motor as a key account specialist.  My first assignment is to cash two checks that I have received. Both were written by a customer who has already received the engines. The total is $2500. I am to cash the checks, get the money, take out my bonus and any other related expenses and deposit into a Bitcoin ATM. Then make copy of receipt and electronically send to my "manager".  I contacted a lawyer, was told to talk to the Department of Labor, who said they will not get involved, as this is between me and my employer. Any advice? Evaluate $\int_{-\pi/4}^{\pi/4}(\cos(t)+\sqrt{1+t^2}\cos(t)^3\sin (t)^3)dt$ Let $f(z)$ be an entire function such that $$|f(z)|&lt;\frac{1}{|\text{Im}(z)|},\qquad z\in\Bbb C-\Bbb R.$$ The question asked me to prove that $f(z)=0$. At least looking at it, it really seems to have an application of Liouville's theorem lurking around somewhere, but I haven't found it.   My thoughts first led me to think about doing this by contradiction and using Picard's little theorem. So, I've considered a strip containing the real axis (say of width $2$ for simplicity). This will imply the complement maps into the unit disk, which implies that this strip has to map almost everywhere else on the complex plane. Now, on the imaginary axis, I know that $f(z)$ will vanish as $z\to\infty$, and this seems like it might be useful. I'm sort of under the impression $f(z)$ might have an essential singularity at $\infty$, which would mean $f(1/z)$ has an essential singularity at $0$. Either way, it of course can't have a pole at $\infty$ because of $f(z)$ vanishing on the imaginary axis, and if it is a removable singularity, it must be $0$, which still gives the solution. Therefore, I think it must have something to do with $f(z)$ having an essential singularity at $\infty$.   I was hoping to combine this with the above inequality and deduce a contradiction, but I haven't thought of one yet.   Any hints or suggestions? I'm studying for a prelim. exam, so this isn't homework.  Update: So, in the spirit of searching methods using the essential singularity at $z=0$, we have $$\left|f\left(\frac{1}{z}\right)\right|\leq\frac{1}{\left|\text{Im}\left(\frac{1}{z}\right)\right|}=\frac{|z|^2}{|y|}.$$ Thus, for $|y|&gt;1$, we have $$\left|f\left(\frac{1}{z}\right)\right|&lt;|y|\left|f\left(\frac{1}{z}\right)\right|&lt;|z|^2.$$ Thus, if I can show that $|f(1/z)|$ is a polynomial, we'll know it can't have an essential singularity at the origin, concluding my proof. How do I pass a function as a parameter to in elisp? I'm trying to pass one method to another in elisp, and then have that method execute it.  Here is an example:  (defun t1 ()   "t1")  (defun t2 ()   "t1")  (defun call-t (t)   ; how do I execute "t"?   (t))  ; How do I pass in method reference? (call-t 't1) What is Kirito's relationship with the girls of SAO? If object A is moving at velocity $v$ (normalized so that $c=1$) relative to a ground observer emits object B at velocity $w$ relative to A, the velocity of B relative to the ground observer is  $$ v \oplus w = \frac{v+w}{1+vw} $$  As expected, $v \oplus 1 = 1$,  as "nothing can go faster than light".  Similarly, $v \oplus -1 = -1$. (same thing in the other direction)  But what if object A is moving at the speed of light and emits object B at the speed of light in the exact opposite direction? In other words, what is the value of $$1 \oplus -1?$$ Putting the values in the formula yields the indeterminate form $\frac{0}{0}$. This invites making sense of things by taking a limit, but $$ \lim_{(v,w)\to (1,-1)} \frac{v+w}{1+vw}$$ is not well-defined, because the limit depends on the path taken.  So what would the ground observer see? Is this even a meaningful question?  Edit: I understand $1 \oplus -1$ doesn't make sense mathematically (thought I made it clear above!), I'm asking what would happen physically. I'm getting the sense that my fears were correct, it's physically a nonsensical situation. What is the number of automorphisms (including identity) for permutation group $S_3$ on 3 letters? What is the number of automorphisms (including identity) for permutation group $S_3$ on 3 letters?  I believe the answer for this is 6. As we can write the group elements as below   (a)(b)(C) (ab)(c) (ac)(b) (bc)(a) (abc) (bac)   Can we generalize that for any $S_n$ onto $n$ the number of automorphisms will be $n!$ Also I cannot find this anywhere in my text, can we have a permutation $S_n$ onto $m$ where $n\neq m$? (for eg: is it possible to have a permutation group say $S_5$ on say 2 elements?)