I'd like to plot the graph in polar coordinates of the function r=f(t)=2/cos(t), which should be a vertical line parallel to the y-axis. I've tried it with two different commands, and below you can see the results

plot(2/cos(theta), coords = polar)

**What is going on here?**

**I then tried using polarplot from the plots package.**

with(plots):

polarplot(2/cos(t), t = 0 .. 2*Pi)

Shouldn't the graph be a vertical line at 2?

Notice that if I plot two similar plots

polarplot([1/cos(t), 2/cos(t)], t = 0 .. 2*Pi)

The same result is obtained

**What is going on here? **