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Zarathuztra
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Homework Statement
The current in a 25mH inductor is known to be - 10A for t <= 0 and (-10cos400t - 5sin400t)e^-200t A for t >= 0. Assume the passive sign convention.
Part A: At what instant of time is the voltage across the inductor maximum?
Part B: What is the maximum voltage?
Homework Equations
V=L*di/dt
The Attempt at a Solution
I took the derivative of (-10cos400t - 5sin400t)e^-200t, then took the derivative again, set to zero, and found the value of t at that point.
5000*e^(-200t)*sin(400t)
1000000*e^(-200t)(2cos400t - sin400t) = 0 @ t = 0.01339 s
Where am I going wrong? Am I missing something?