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.
Painful menstrual periods are periods in which a woman has crampy lower abdominal pain, sharp or aching pain that comes and goes, or possibly back pain. Some pain during your period is normal, but a large amount of pain is not. The medical term for painful menstrual periods is dysmenorrhea. Many women have painful periods. Sometimes, the pain makes it hard to do normal household, job, or school-related activities for a few days during each menstrual cycle.