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.
Fast facts on menstrual cramps. Here are some key points about menstrual cramps. More detail and supporting information is in the main article. 1  Menstrual cramps are pains felt in the lower abdomen, occurring both before and during a woman's menstrual period. 2  The pain can be slight or sometimes extremely severe. 3  There are two types of painful periods-primary and secondary dysmenorrhea.