So I bought a Nest Thermostat off amazon, I read they used batteries and what not and after I purchased it I was looking at the description on amazon and it said it was a built in rechargeable battery (face palm) I have a 4 wire I don't have a common, I was wondering if it's safe or reasonable that,  I have a light switch basically a foot below the thermostat so I was going to install a 40va step down transformer to power the thermostat using the R as the hot from the transformer and the C as the neutral from the transformer, does this pose any issues? I googled it but people seem 50/50 some say it's great some say it's not a good fix and to pull a new wire, but pulling a new wire at this point in time is not an option. If I left the R straight from the furnace and just used the neutral from the transformer would that be worse than setup 1? (Using the hot and neutral from the transformer) as far as I know all the thermostat does is use that power to close and open contacts in the thermostat so it shouldn't matter if the tstat is powered off a transformer, should it?  Sorry for poor phrasing wrote on phone.
Update 02/02/2019 I appreciate all the responses and help but unfortunately i must have not seen the emails stating there were responses! I am now looking into a NEST thermostat and was curious if they too, use the same connections. Lastly, looking for a quick recommendation on which WiFi Compatible therms are preferred by the memebers that respond! Thanks again your knowledge is highly appreciated! Bob  I Purchased the Honeywell WiFi Prog Thermostat to replace my Round Digital Honeywell Thermostat. I have separate Heating and Cooling (Heating is a Weil McLain Boiler for Hot water baseboard and Hot water(no tank) and Cooling is a separate unit that was added later.)  Wires:  RC Cool R Heat W Heat Y Cool G Cool   3 wires from AC unit and 2 from Heater.  If I were to go the separate transformer route to power the thermostat, where would I land the 2 wires?  C and ???
Second order partial of $f(x,y)=\frac{xy(x^2-y^2)}{x^2+y^2}$ Consider the function $f(x,y)=\dfrac{xy(x^2-y^2)}{x^2+y^2}$ for $(x,y) \neq (0,0)$, $f=0$ otherwise.  I have to compute $\dfrac{d^2f}{dydx}(0,0)$.  I know that I have to calculate $\frac{df}{dx}$ first. But that is ,  $\frac{df}{dx} = \frac{\partial f}{\partial y}\frac{dy}{dx}+\frac{\partial f}{\partial x}$. When I put it in wolframalpha, it gives me this calculation, and also just $\frac{\partial f}{\partial x}$ as an alternative form.   Why do I just ignore the y'? I don't know what y(x) is, as a function of x.  y and x are independent functions, no? Show that $\lim _{r \to 0} \|T_rf−f\|_{L_p} =0.$ Pagination go to first page if i'm on last post I have a custom post type and used get_next_post() and get_previous_post() to create a simple pagination. However i need to create a pagination loop (if that is the correct term). If i'm on the first post i need to browse back to the last post and if i'm on the last post i need to browse to the first post. Is there a simple way to do this that i haven't seen but Google, this site and the codex has not been very helpfull :/  The current code i have is. I've tried to use wp_list_pages and other functions but with little luck.  $next_post = get_next_post(); $prev_post = get_previous_post(); $nav = array(     "next_post" =&gt; array(         "url"       =&gt; get_permalink($next_post-&gt;ID),         "id"        =&gt; $next_post-&gt;ID,         "titill"    =&gt; get_field("vinstri_titill", $next_post-&gt;ID)." - ".get_field("vinstri_undirtitill", $next_post-&gt;ID)     ),     "prev_post" =&gt; array(         "url"       =&gt; get_permalink($prev_post-&gt;ID),         "id"        =&gt; $prev_post-&gt;ID,         "titill"    =&gt; get_field("vinstri_titill", $prev_post-&gt;ID)." - ".get_field("vinstri_undirtitill", $prev_post-&gt;ID)     ), ); Using Replace Geometry to replace selected feature with circle in ArcGIS Desktop? I have a polygon shapefile and I want replace every irregular polygon with a circle.  I think I can do it with the Replace Geometry tool. But once the Replace Geometry tool is selected, draw a polygon mode is immediately entered. If I select the circle tool in the Draw tool window, the Replace Geometry tool becomes inactive.  Is there any way to use the Replace Geometry tool to draw a circle polygon? How much hard disk space should be needed for Xbox 360? I want to get a 360 and don't know wether to get the bigger (250GB), newer, more expensive Elite, or get one of the older, smaller (120GB), last gen ones. I know the arcade is going to be too small to save anything useful  How much hard disk space is recommend? What else is stored besides games? Increasing the size of tyres on a hybrid We are planning on doing some mountain biking in a few weeks time and we'd like to get some wider tyres for my wife's hybrid. I know there are similar questions and answers out there on this topic, but I need some specific help to make sure I buy the right tyres.  The bike is a Ladies Scott Sportster 50 2015, the best website I could find with a fairly accurate spec is     It's currently got Kenda K-180 700 x 38c / 30TPI tyres on it, which are fairly good all rounders and capable of running on clean forest paths but I don't think they would handle anything heavier.  It's got disk brakes so there isn't a clearance issue there, but I have noticed the frame is generally narrower than true MTBs, here are some photos i took of it.    Has anyone put larger, knobblier tyres on this kind of hybrid? whats the largest I can get away with? - I'm also slightly confused by all the tyre sizing, I'm sure someone told me this is a 27.5" tyre, but 700 seems to mean 29" on a lot of websites.  Any advice is very much appreciated, Thanks. Between you and ("me" or "I")? I have a question, to aid my understanding, about the proof that differentiability implies continutity.$\mathstrut$    Differentiability Definition  When we say a function is differentiable at $x_0$, we mean that the limit:  $$‎f^{\prime} ‎(x) = \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0}$$ exists.  Continuity Definition  When we say a function is continuous at $x_0$, we mean that: $$\lim_{x\to x_0} f(x) - f(x_0) = 0$$  Theorem: Differentiability implies Continuity: If $f$ is a differentiable function at $x_0$, then it is continuous at $x_0$.  Proof:  Let us suppose that $f$ is differentiable at $x_0$. Then $$ \lim_{x\to x_0} \frac{f(x) - f(x_0)}{x-x_0} =  ‎f^{\prime} ‎(x) $$  and hence  $$ \lim_{x\to x_0} f(x) - f(x_0) = \lim_{x\to x_0} \left[ \frac{f(x) - f(x_0)}{x-x_0} \right] \cdot \lim_{x\to x_0} (x-x_0) = 0$$  We have therefore shown that, using the definition of continuous, if the function is differentiable at $x_0$, it must also be continuous.  My Question  The proof seems to execute the following steps:   Assume the function is continuous at $x_0$ Show that, with little algebra, we can change this into an equivalent question about differentiability at $x_0$. With this little bit of algebra, we can show that if a function is differentiable at $x_0$ it is also continuous.   What I am slightly unsure about is the apparent circularity. In my mind it seems to say, if a function is continuous, we can show that if it is also differentiable, then it is continuous. Rather than what I was expecting, namely, if a function is differentiable, we can show it must be continuous.  Hopefully my confusion is clear. Any help will be greatly appreciated. What is the advantage on saving the money for the overlord when you have 9 drones, and not filling your supply first and then getting the overlord?  In my theory, in the first case you get to wait the saving time with 9 drones, and get to wait almost the same time with 10 drones in the second case. Second case should be better, since 10 drones mine faster than 9? So why does everybody go with the first case?  All this is assuming you go 12 pool or something like that, where you will get more drones after the overlord. 6- and 8-pools are obviously different. Two circles intersection Could you tell what are all the four points in following? Two circles intersect at two points maximum when we want to draw intersecting circles. But there we are solving quadratic equations, what is the argument about the other two missing points ? Movie with killer androids (glowing eyes, screaming) Based on , I figured that there might be multiple questions for distinct locales. Why do the most common transactions to or from bank accounts in the US require waiting one or more days before they are completed? In the information age, it seems like we should be able to transfer money instantly (or nearly so). Switching baselayers as user zooms in to map in OpenLayers? Resistance between two points in an infinite metal sphere/cube Let's imagine that we have a tridimensional metal object of infinite size, and decide to calculate the resistance between two arbitrary points. How would we go about doing this?  I have thought of two possibilities for calculating this, the first one being an adaptation of the conductivity (S/m) using the Pythagorean theorem to find a distance and isolating the resistance from there, treating it like we would treat an electrolytic liquid.  The second possibility I have been thinking about would be a 3-dimentional adaptation of the infinite-resistors problem (which I have only seen in 2d).  Would one of these methods result in giving a decent approximation, or would another method give better results? What bike+equipment for a long daily urban commute? In the (distant) past I commuted 6 km (more than half an hour) each way, on a cheap bike with big knobbly tyres.  Soon I'll have a new commute: 18 km each way, daily. That's much further than I've done in the past, and I don't want it to take 2 hours each way; but  suggests that it's feasible:      Most people who reside 10 to 20 kilometres away will also find it quite easy to cycle to work, although the distance in the high end of this range will become a little more demanding.   If I can do it in 80 minutes or even less each way, that would be ideal. I'm 49 years old, 6 foot tall, and weigh 170lb, and I want to commute by bike because otherwise I'd be getting no exercise in my week at all.  I've never bought or ridden anything but a cheap bike.  What equipment should I buy then, to commute 11 miles each way through a city (Toronto) on  flat, paved roads, shared with cars:   Wheels? Tyres? Clipless pedals and shoes? Gears? Handlebars (e.g. flat or dropped)? Frame (size, shape, material)? Mud-guard/fender? The  was observed, giving us the frequency and amplitude of the event. Because LIGO has two detectors a  could be derived.  But how do these three factors allow for the mass of the black holes and their distance to be calculcated? If the wave strengths are in a square relationship to distance, then couldn't there be an infinite number of other masses and distances which would give the same signals? Give an example of a relation R on $A^2$ which is reflexive, symmetric, and not transitive I am just looking for some clarification on this exercise:  Let $A = \{a,b,c,d\}$. Give an example of a relation $R$ on $A^2$ which is reflexive, symmetric, and not transitive.  I understand that if I was only dealing with $A$ and and not $A^2$ I could give an answer similar to:  $R = \{(a,a),(a,b),(a,d),(b,a),(b,b),(c,c),(d,a),(d,d)\}$  Here $R$ is reflexive, symmetric, and not transitive.  What is confusing me is the fact that we have $A^2$. I am not sure what I am missing here. I am looking through my book to see if I can figure this out, but if someone could help shed some light on this it would be appreciated.  Thanks,  Tony How to get a function name as a string? In Python, how do I get a function name as a string, without calling the function?  def my_function():     pass  print get_function_name_as_string(my_function) # my_function is not in quotes   should output "my_function".  Is such function available in Python? If not, any ideas on how to implement get_function_name_as_string, in Python? Difference between 2 numbers I need the perfect algorithm or C# function to calculate the difference (distance) between 2 decimal numbers.  For example the difference between: 100 and 25 is 75 100 and -25 is 125 -100 and -115 is 15 -500 and 100 is 600  Is there a C# function or a very elegant algorithm to calculate this or I have to go and handle every case separately with ifs.  If there is such a function or algorithm, which one is it? Compactness of a Sphere This fact is mentioned liberally in literature along with subsequent mention of Heine-Borel and I am trying to get my head around it. What would be a formal proof of this if we take for example, a unit sphere in $\mathbb R^3 $?  In addition, how could it be shown, non-trivially of course, that this sphere is not homeomorphic with $\mathbb R^2 $? As I understand this involves finding a bijective function with continuous inverse?