Differential Eqs. Flashcards
1
Q
What is the form of the G.S when the aux is 2 real roots?
A
y = Ae^cx + Be^dx
2
Q
What is the form of the G.S when the aux is one repeated root?
A
y = (A+Bx)e^cx
3
Q
What is the form of the G.S when the aux has complex roots?
A
y = e^px(Acosqx + Bsinqx), p is real part, q is imaginary.
4
Q
How do you use the P.I?
A
Differentiate as many times as needed, sub back in to find (hopefully) values of P.I, then add this to general solution.
5
Q
How do you use boundary conditions?
A
To find a particular solution. Lets you find A and B.
6
Q
What is the integrating factor?
A
For dy/dx + P(x)y = Q(x), mult every term by factor e^ integral of P(x). Then group into d/dx.
