Consider the differential equation ay__ + by_ + cy = 0, where b24ac < 0 and the
Chapter 3, Problem 23(choose chapter or problem)
Consider the differential equation ay__ + by_ + cy = 0, where b24ac < 0 and the characteristic equation has complex roots i. Substitute the functions u(t) = et cos(t) and v(t) = et sin(t) for y in the differential equation and thereby confirm that they are solutions.
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