For an electric circuit, let V=cos 2pi(t) model the electromotive force in volts at t seconds.
find smallest positive value of t where 0<and= to t<and= to 1/2 for the values
a) sub to get 0 = cos(2pi*t)
but we know that cos is 0 at pi/2 hence
2pi*t = pi/2
t = ...
Minimum time is linked to voltage in this electromotive force problem.