3) Critically damped: [math]x(t) = (A + Bt)e^{- \gamma t}[/math] This is the optimally damped case, where the damping coefficient is just large enough to completely quell the oscillations, so the oscillator returns to zero in the least amount of time possible. 4) Overdamped: [math]x(t) = Ae^{- \gamma_{1}t} + Be^{- \gamma_{2}t}[/math]
DEAR READER: A woman is considered to be in menopause once it has been one year since her last period. Once menopause begins, vaginal bleeding is not normal. Post-menopausal bleeding (PMB) can happen for many reasons. It may result from infection or injury. Non-cancerous growths such as polyps and fibroids can cause PMB. So can bleeding disorders or use of blood thinners.
Some people call the years leading up to a woman's last period menopause, but that time actually is the menopausal transition, or perimenopause (PER-ee-MEN-oh-pawz). During the time of the menopausal transition (perimenopause), your periods can stop for a while and then start again. Therefore, the only way to know if you have gone through menopause is if you have not had your period for one year. (And it's not menopause if your periods stop for some other reason, like being sick.) The average age of menopause is 51, but for some women it happens as early as 40 or as late as 55.