(The DC Component): This Dirac delta at the origin represents the average value (or DC offset) of the function. Since
Here lies the contradiction: the term $e^-i\omega t$ is oscillatory (it contains sine and cosine components). As $t \to \infty$, it does not decay to zero; it merely oscillates indefinitely. Therefore, under standard calculus rules, the integral does not converge. The Heaviside function is not "square integrable," meaning its energy is infinite. To solve this, we must invoke the theory of distributions. fourier transform of heaviside step function
Here:
This integral converges nicely: $$ \left[ \frace^-(\sigma + i\omega)t-(\sigma + i\omega) \right]_0^\infty = 0 - \left( \frac1-(\sigma + i\omega) \right) = \frac1\sigma + i\omega $$ (The DC Component): This Dirac delta at the