Standard: HSF.TF.B7 – (+) Use inverse functions to solve trigonometric equations that arise in modeling contexts; evaluate the solutions using technology, and interpret them in terms of the context.*
Grade level: High School: Functions
Subject: Mathematics
Domain: Trigonometric Functions
Teacher Overview
This standard focuses on using inverse trigonometric functions to solve equations in modeling contexts, an essential skill in advanced mathematics. Mastery of this standard enables students to interpret and solve real-world problems involving periodic phenomena, enhancing their analytical and problem-solving skills. Students need a robust understanding of trigonometric functions, inverse functions, and basic algebraic manipulation. Prior exposure to using technology for graphing and solving equations will also be beneficial.
Mastery of this standard prepares students for advanced topics in trigonometry and calculus, where they will encounter more complex equations and applications in various scientific fields.
Common Misconception 1
A common misconception is that inverse trigonometric functions are used in the same way as regular trigonometric functions. This is incorrect because inverse functions are specifically used to find angles when given a ratio, whereas regular functions are used to find ratios when given an angle.
Intervention 1
To address this misconception, use side-by-side examples of problems solved with trigonometric functions and their inverses. Highlight the different steps and conditions for each type of function.
Common Misconception 2
Another misconception is that trigonometric equations have only one solution. This is incorrect as many trigonometric equations have multiple solutions due to the periodic nature of trigonometric functions.
Intervention 2
Use graphing technology to show multiple solutions on a graph. Provide real-world examples where multiple solutions are valid and necessary, such as determining angles in navigation.
Prerequisite Knowledge
Students should have a strong understanding of basic trigonometric functions, their properties, and how to manipulate them algebraically. They should also be familiar with the concept of inverse functions and how to use them.
Subsequent Knowledge
After mastering this standard, students will be able to tackle more complex trigonometric identities and equations, and apply their knowledge to real-world problems in physics, engineering, and other STEM fields.
Instructional Activities
- Graphing trigonometric functions and their inverses using graphing calculators or software
- Solving real-world problems involving angles and distances
- Group projects modeling periodic phenomena in different contexts
- Using online simulations to visualize trigonometric concepts
- Class discussions on the applications of trigonometric functions in various careers

