Questions: The Laplace transform of a continuous function over the interval [0, ∞) is defined by F(s)=∫ from 0 to ∞ e^(-sx) f(x) dx. This definition is used to solve some important initial-value problems in differential equations. The domain of F is the set of all real numbers s such that the improper integral converges. Find the Laplace transform F of the following function:
f(x)=6x
Transcript text: The Laplace transform of a continuous function over the interval $[0, \infty)$ is defined by $F(s)=\int_{0}^{\infty} e^{-s x} f(x) d x$. This definition is used to solve some important initial-value problems in differential equations. The domain of $F$ is the set of all real numbers $s$ such that the improper integral converges. Find the Laplace transform $F$ of the following function:
\[
f(x)=6 x
\]
Solution
Solution Steps
Step 1: Define the Function
We start with the function \( f(x) = 6x \).
Step 2: Set Up the Laplace Transform
The Laplace transform \( F(s) \) is defined as:
\[
F(s) = \int_{0}^{\infty} e^{-sx} f(x) \, dx
\]
Substituting \( f(x) \) into the equation, we have:
\[
F(s) = \int_{0}^{\infty} e^{-sx} (6x) \, dx
\]
Step 3: Evaluate the Integral
To evaluate the integral, we recognize that it can be computed using integration by parts. The result of the integral is:
\[
F(s) = \frac{6}{s^2} \quad \text{for } |s| < \frac{\pi}{2}
\]
Final Answer
Thus, the Laplace transform of the function \( f(x) = 6x \) is:
\[
\boxed{F(s) = \frac{6}{s^2}}
\]