\(y''+4y'+3y=e^{-t}\),\(y(0)=y'(0)=1\)的解为\(y(t)=\frac{1}{4}[(7+2t)e^{-t}-3e^{-3t}]\) ( )
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\(L^{-1}[\frac{s}{(s+2)(s+4)}]\)的值为( )
A. \(e^{-4t}-e^{-2t}\)
B. \(2e^{-4t}-e^{-2t}\)
C. \(e^{-2t}-e^{-4t}\)
若\(L[f(t)]=F(s)\),\(L[g(t)]=G(s)\)则\(L[f(t)*g(t)]\)为( )
A. \(F(s)\cdot G(s)\)
B. \(F(s)+G(s)\)
C. \(F(s)*G(s)\)
若\(L[f(t)]=\frac{1}{s+a}\),则\(f(0)\)为( )
A. 0
B. \(\frac{1}{a}\)
C. 1
已知\(L[e^{-at}]=\dfrac{1}{s+a}\),则\(L[te^{-at}]\)为( )
A. \(\dfrac{1}{s(s+a)}\)
B. \(\dfrac{1}{s^2(s+a)}\)
C. \(\dfrac{1}{(s+a)^2}\)