2011年9月26日 · Actually I've never seen that use of it. I'm not saying it's wrong, but it's unusual. But in elementary math texts, [itex]\Delta[/itex]x means the amount of change in the variable x.

2012年5月4日 · The delta function doesn't really have a well-defined meaning outside of an integral, so as far as we're concerned, if integrating f(x) against [itex]\delta(x-a)[/itex] or [itex]\delta(a-x)[/itex] gives you the same result, then [itex]\delta(x-a) = \delta(a-x)[/itex].

2010年9月10日 · [itex]\delta x[/itex] is a number but is only an approximation to dx. In calculus, "dx" is essentially a "concept" rather than an actual number- and dy is defined by "dy= (dy/dx) dx" where "dy/dx" is, of course, the derivative.

2016年7月24日 · The ##\delta x## denotes rather a variation in variational calculus, e.g., in the Lagrange formalism of classical mechanics, where you have an action functional ##A[x]=\int_{t_1}^{t_2} \mathrm{d} t L(x,\dot{x}).## Then ##\delta x## …

2014年4月13日 · But there we have [itex]\delta'(-x)=-\delta'(x)[/itex]. I think if you want to see why the Dirac delta is an "even" distribution is to go back to the definition: [itex] \int_{I(0)} \delta(x) f(x) dx = f(0) [/itex] where [itex]I(0)[/itex] is a neighbourhood of 0. Now let's see what happens if we use [itex]\delta(-x)[/itex] instead:

2013年9月17日 · Suppose that at time ##t_0## a car starts at a point ##x_0## and travels to point x arriving at time t. Then the average velocity of the car over its trip is ## \Delta x/ \Delta t = \frac {x-x_0}{t-t_0}## -- that is the change in distance divided by the change in time. This tells you nothing about the velocity at any given moment.

2008年3月2日 · Physics news on Phys.org . When systems suddenly tip: New insights into hard-to-predict transitions; Meters closer, miles faster: A novel cryogenic in-memory computing scheme to bridge AI with quantum computing

2004年10月3日 · It can also be written as dx/dt or delta x/delta t. [meaning velocity is a small change in position per small change in time] a is acceleration. [ how fast the velocity is changing] It can also be written as dv/dt or delta v/delta t. [meaning acceleration is a small change in velocity per small change in time] x(t) is position as a function of time

2010年1月21日 · Using the defining property of the dirac delta function, \int{dx f(x) \delta(x-c)} show that \delta(ax)=\frac{1}{|a|}\delta(x) I think all I need to do... Insights Blog -- Browse All Articles -- Physics Articles Physics Tutorials Physics Guides Physics FAQ Math Articles Math Tutorials Math Guides Math FAQ Education Articles Education Guides Bio ...

2008年9月12日 · Hello everyone Today in my QM class, a discussion arose on the definition of the delta function using the Heaviside step function \\Theta(x) (= 0 for x < 0 and 1 for x > 0). Specifically, \\Theta(x) = \\int_{-\\infty}^{x}\\delta(t) dt which …