The general solutions for the harmonic oscillator differential equation fall into four general categories: 1) Undamped: [math]x(t) = Ae^{i\omega t}[/math] This is a free-running sinusoidal oscillation that doesn't change over time.
Key Facts. 1  Itâs normal to have mild cramps during your period. 2  Menstrual cramps often start 1-2 days after your period begins. 3  If your cramps donât get better with over-the-counter medicine, you should see your health care provider.
Menstrual cramps are pains in a woman's lower abdomen that occur when her menstrual period begins (or just before) and may continue for two to three days. They may be throbbing or aching and can be dull or sharp. Symptoms can range in severity from a mild annoyance to severe pain that interferes with normal activities.