If possible, redefine the function to make it continuous.
\(f(x) = \frac{cos^2 x}{1 - sin^3 x},\) for x < \(\frac{\pi}{2}\)
f(x) = (cos2x)/(1 - sin3 x), for x < π/2
\(=\frac{\sqrt{2}-\sqrt{1 + sin\,x}}{cos^2 x},\) for x > \(\frac{\pi}{2}\)
\(=\frac{2}{3},\) for x = \(\frac{\pi}{2};\) at x = \(\frac{\pi}{2}.\)