Section 4 List

\begin{itemize}
  \item Sine addition formula
  \item Cosine addition formula
\end{itemize}

• •
  Sine addition formula
• •
  Cosine addition formula

\begin{itemize}
  \item Sine addition formula
  \begin{itemize}
    \item $\sin(x+y)=\sin x\cos y + \cos x\sin y$
    \item $\sin(x-y)=\sin x\cos y - \cos x\sin y$
  \end{itemize}
  \item Cosine addition formula
  \begin{itemize}
    \item $\cos(x+y)=\cos x\cos y - \sin x\sin y$
    \item $\cos(x-y)=\cos x\cos y + \sin x\sin y$
    \begin{itemize}
      \item Note 1
      \item Note 2
    \end{itemize}
  \end{itemize}
\end{itemize}

• •
  Sine addition formula

  • –
    ​\(\sin (x+y)=\sin x\cos y + \cos x\sin y\)
  • –
    ​\(\sin (x-y)=\sin x\cos y - \cos x\sin y\)
• •
  Cosine addition formula

  • –
    ​\(\cos (x+y)=\cos x\cos y - \sin x\sin y\)
  • –
    ​\(\cos (x-y)=\cos x\cos y + \sin x\sin y\)

    • *
      Note 1
    • *
      Note 2

\begin{enumerate}
  \item $\sin(x+y)=\sin x\cos y + \cos x\sin y$
  \item $\cos(x+y)=\cos x\cos y - \sin x\sin y$
\end{enumerate}

• 1.
  ​\(\sin (x+y)=\sin x\cos y + \cos x\sin y\)
• 2.
  ​\(\cos (x+y)=\cos x\cos y - \sin x\sin y\)

\begin{enumerate}
  \item Sine addition formula
  \begin{enumerate}
    \item $\sin(x+y)=\sin x\cos y + \cos x\sin y$
    \item $\sin(x-y)=\sin x\cos y - \cos x\sin y$
  \end{enumerate}
  \item Cosine addition formula
  \begin{enumerate}
    \item $\cos(x+y)=\cos x\cos y - \sin x\sin y$
    \item $\cos(x-y)=\cos x\cos y + \sin x\sin y$
    \begin{enumerate}
      \item Note 1
      \item Note 2
    \end{enumerate}
  \end{enumerate}
\end{enumerate}

• 1.
  Sine addition formula

  • (a)
    ​\(\sin (x+y)=\sin x\cos y + \cos x\sin y\)
  • (b)
    ​\(\sin (x-y)=\sin x\cos y - \cos x\sin y\)
• 2.
  Cosine addition formula

  • (a)
    ​\(\cos (x+y)=\cos x\cos y - \sin x\sin y\)
  • (b)
    ​\(\cos (x-y)=\cos x\cos y + \sin x\sin y\)

    • i.
      Note 1
    • ii.
      Note 2

\begin{description}
  \item[Sine addition formula:] $\sin(x+y)=\sin x\cos y + \cos x\sin y$
  \item[Cosine addition formula:] $\cos(x+y)=\cos x\cos y - \sin x\sin y$
\end{description}

• Sine addition formula:
  ​\(\sin (x+y)=\sin x\cos y + \cos x\sin y\)
• Cosine addition formula:
  ​\(\cos (x+y)=\cos x\cos y - \sin x\sin y\)