22: L'Hospital leads to
There is another indeterminate ratio. While l'Hospital's rule does help, it is probably simpler to use the approach from the box "polynomials and ratios with powers". There are two ways to identify leading powers for cancelling. The standard approach is to multiply out the square in the denominator to change it into a traditional polynomial. Somewhat better way is to pull the square out of the fraction and cancel in the resulting simpler fraction.