1.0 milliseconds -- cycle time for frequency 1 kHz
1 ms -- duration of light for typical photo flash strobe
2.27 ms -- cycle time for the A above middle C in music (440 Hz). If an electric tuning device for musical instruments generates just one tone, this is probably that tone.
... quadratic formula expresses the explicit solution(s) x to the quadratic equation
<math>ax^2+bx+c=0</math>
in terms of the coefficients a, b and ...