Chapter 28, Problem 38P

In contrast to Prob. 28.37, real resistors may not always obey Ohm's law. For example, the voltage drop may be nonlinear and the circuit dynamics is described by a relationship such as

$L\frac{di}{dt}+R\left[\frac{i}{I}-{\left(\frac{i}{I}\right)}^3\right]=0$

where all other parameters are as defined in Prob. 28.37 and I is a known reference current equal to 1. Solve for i as a function of time under the same conditions as specified in Prob. 28.37.