Question 729912
For any function y = Asec(Bx-C)+D the period is {{{2pi/B}}}.<P>
For {{{y=-2sec(pi*x/2)}}} B is {{{pi/2}}} so the period is {{{2pi/(pi/2) = 2pi*2/pi=4}}}<P>
For {{{y= (1/2)*sec(pi*x/2)}}} B is {{{pi/2}}} so the period is {{{2pi/(pi/2) = 2pi*2/pi=4}}}