Trigonometric Identity Proving is a common question type that is included in the O-Level Additional Math syllabus. The mention of “trigo proving” would often cause even the top secondary school students to break out in cold sweat.
Trig Identities Problem Solver
The only way to develop problem solving skills is by solving problems. The only way not to skip problem solving is to put it in the beginning of the lessons, use it in teaching the concept than as applications after learning the concepts only. I have shared sample lessons on teaching integers and algebraic expressions via problem solving in this blog. This time I’ll share a trigonometry lesson through PowerPoint presentation. The lesson is an introductory lesson on tangent and cotangent. The lesson shows how you can introduce these concept as ratios and as functions.
- Proving Trigonometric Identities (page 1 of 3) Proving an identity is very different in concept from solving an equation. Though you'll use many of the same techniques, they are not the same, and the differences are what can cause you problems.
- Sine Addition Formula Starting with the cofunction identities, the sine addition formula is derived by applying the cosine difference formula. There are two main differences from the cosine formula: (1) the sine addition formula adds both terms, where the cosine addition formula subtracts and the subtraction formula adds; and (2) the sine formulas have sin-sin and cos-cos.
Features of the lesson
- The problems have many solutions
- Links new concepts to previously learned knowledge
- Problems are in real-life contexts
- Shows geometric and algebraic (function) side of trigonometry
- Students compares and evaluates different solutions
The presentation shows the teacher the flow of the lesson. Use it after the students have solved the problems in different ways, as a way of summarizing the possible solutions. Crucial to the lesson is slide #10 which contains questions for discussing the students’ solutions and the link between the previously learned concepts and the new concepts introduced in this lesson.
Trigonometric Identities Practice Problems
