2.6.  IMPORTANT PROPERTIES OF THE LAPLACE TRANSFORM

The Laplace transform has been introduced in order to simplify several mathematical operations. These operations center upon the solution of linear differential equations. Several basic properties of the Laplace transform are given here.

A.  Addition and Subtraction

If the Laplace transforms of f1(t) and f2(t) are F1(s) and F2(s), respectively, then

Image[f1(t) ± f2(t)] = F1(s) ± F2(s).

B.  Multiplication by a Constant

If the Laplace transform of f(t) is F(s), the multiplication of the function f(t) by a constant K results in a Laplace transform KF(s).

C.  Direct Transforms of Derivatives

If the Laplace transform of f(t) is F(s), the transform of the first time derivative Image(t) of f(t) is given by

Image

where f(0+) is the initial value of f(t), evaluated as t → 0 from the positive region. The transform of the second time derivative Image(t) of f(t) is given by

Image

where (0+) is the first derivative of f(t) evaluated at t = 0+. The Laplace transform of the ...

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