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hils0005
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[SOLVED] Tough Diff EQ problem
y^(4)-8y^(2)-9y=7e^(-3x)
y^(4)=fourth derivative, y^(2)=second deriv.
Need to find complimentary solution and particular solution using variation of parameters
r^4-8r^2-9=0
(r^2-9)(r^2+1)=0, r=9,-1
Y(c)=Ce^(9x)+Ce^(-x)
I think the comp soln is right, but I am unsure on how to start on Y(p)
Homework Statement
y^(4)-8y^(2)-9y=7e^(-3x)
y^(4)=fourth derivative, y^(2)=second deriv.
Homework Equations
Need to find complimentary solution and particular solution using variation of parameters
The Attempt at a Solution
r^4-8r^2-9=0
(r^2-9)(r^2+1)=0, r=9,-1
Y(c)=Ce^(9x)+Ce^(-x)
I think the comp soln is right, but I am unsure on how to start on Y(p)