By itself, sec(x) is not easy to work with, since we haven't really spent a lot of time learning the values associated with it. How can we put it in the form of something simpler? Well, remember that:
sec(x) = 1/cos(x)
Hence, we'll have:
sec^2(pi) = [1/cos(pi)]^2 = 1/cos^2(pi)
You should know that cos(pi) = -1 from the unit circle. Because we're squaring the cos(x), the negative sign simply goes away, so we're left with:
1/1 = color(red)(1)
Check out the graph of sec^2(x) below. Notice how it has the coordinate (pi, 1):
graph{y = (sec(x))^2 [-10, 10, -5, 5]}
Hope that helped :)
