No, silver was never used in BX cable.
It used to be, but now the ground wire (which replaced the aluminum strip) in the BX cable is used. The ground wire is now used to complete the grounding of connected devices rather that the sheath of the BX.
ax^2+bx+c=0 is the standard form of a quadratic function.
f(x) = bX is not an exponential function so the question makes no sense.
It's a telephone switchboard
y = x2 is the parent function, but it can be in the form y = ax2 + bx + c
ax2 +bx + c = 0
y = ax2 + bx + c
It is a quadratic function which represents a parabola.
A second-degree polynomial function is a function of the form: P(x) = ax2 + bx + cWhere a ≠ 0.
(0,a)
They can as they will support the wire into the box. The deciding factor should be the cost. A BX connector costs about four times the price of a romex connector. Also to keep in mind is that most junction boxes these days have their own built in clamps.