Laplace Transform Lab
Explore forward Laplace transform pairs for core function families, their poles, region of convergence, and initial/final values.
Frequency domain mapping of differential systems 🖖
The Laplace transform converts a time-domain differential equation into a complex algebraic equation using the integral L{f(t)} = ∫ e^{-st} f(t) dt. Statically, this maps differentiation to multiplication by s, making complex transient dynamics (such as mechanical vibration or circuit resonance) solvable through basic algebra before transforming the solution back to the time domain.
A dictionary between time and s 🖖
At heart this tool is a translation table. Every function of time — a step, a ramp, a decaying exponential — has a matching partner in the s-domain, and the lab shows both sides of each pair. Solve your problem in the easier s-domain, then translate the answer back using these pairs. Concrete takeaway: a decay e^{-at} always maps to 1/(s+a), and the number a tells you how fast it fades.
The engineer who scandalized the mathematicians 🖖
Long before the transform was made rigorous, the self-taught engineer Oliver Heaviside solved circuit equations by boldly treating the derivative operator d/dt as an ordinary algebraic symbol — even dividing by it. Pure mathematicians were appalled by the lack of proof; he reportedly retorted, "Shall I refuse my dinner because I do not fully understand digestion?" His step function still bears his name, and the Laplace transform later supplied the rigor he never bothered with.
Example problems
- step function - Constant step function transforms to a single pole at the origin.
- Example 2 - ramp sample case
- Example 3 - pow sample case
- exponential decay - Exponential decay corresponds to a real pole in the left-half s-plane.
- sine wave - Sine oscillation transforms to a pair of conjugate poles on the imaginary axis.
- Example 6 - cos sample case
- damped sine - Damped sine combines real decay and imaginary frequency into complex pole pairs.
- Example 8 - dcos sample case