Chapter 2 - Limits - 2.6 Trigonometric Limits - Exercises - Page 77: 25

$\frac{ 2\sqrt 2}{ {\pi} }$

\begin{align*} \lim _{t\rightarrow \frac{\pi}{4}} \frac{ \sin t}{t } &=\frac{ \sin \frac{\pi}{4}}{ \frac{\pi}{4} }\\ &=\frac{ \sqrt 2}{ 2\frac{\pi}{4} }\\ &=\frac{ 2\sqrt 2}{ {\pi} }. \end{align*}