\chapter{Trigonometry}
\section{Applications of trig functions}
Answer the questions.
\begin{enumerate}
\item
Explain why we can find the exact value of \(\sin (60^\circ)\) but not the exact value
of \(\sin(60)\).
\item
A scientific calculator only has keys for \(\sin\), \(\cos\), \(\tan\). Explain how to find the other
three functions \(\csc\), \(\sec\), \(\cot\).
\item
Suppose we know the value of \(\theta\) in the following picture:
\[
\img{U4_6F9.png}{}{18em}{}.
\]
Explain how to find \(b\) and \(c\).
\item
The picture shows a building and the light of sight to the top from a point on the ground.
Which of \(\theta_1\), \(\theta_2\), \(\theta_3\) is the angle of elevation?
\[
\img{U4_6F10.png}{}{15em}{}
\]
\end{enumerate}