Limit with the cosine
A standard limit with the cosine is
Explanation
Substitution of x→0 in this limit gives the undefined result
Therefore we can apply l'Hôpital's rule to it
so that
This is an important trigonometric limit.
A standard limit with the cosine is
Substitution of x→0 in this limit gives the undefined result
Therefore we can apply l'Hôpital's rule to it
so that
This is an important trigonometric limit.