Recent content by ch3cooh

Are you referring to this formula $$\frac{df}{dt} = \{f, H\} + \frac{\partial f}{\partial t} $$ As for infinitesimal transformation, it is just the radius ##r## changes. For example, we may have a infinitesimal canonical transformation $$Q = q + \alpha G(q,P)$$ where ##\alpha## is...

Chebyshev polynomials and Legendre polynomials are both orthogonal polynomials for determining the least square approximation of a function. Aren't they supposed to give the same result for a given function? I tried mathematica but the I didn't get the same answer :( Is this precision problem or...

Is there any current flows from point A to the ground (see the attachment)? We use ground node to idicate somewhere in the circuit has ZERO electrical potential. Do we really connect that point to the ground in real world or we just mark that point to make it easier to do calculations?

Is a resistor a voltage-controlled current source? WHY? I think it is but I don't know whether I'm correct.