This document outlines a lesson plan on sinusoidal functions. It includes learning objectives to identify sinusoidal functions and solve word problems using their properties. An investigation section poses questions about the graphical properties of sinusoidal functions, such as whether the curve repeats, has maxima/minima, and restrictions on the domain. The lesson plan involves guided work, pair work, and a plenary session, concluding with a closure activity asking students to summarize their key learnings.