Worksheet
Curated OER

Word Ladders

For Students 9th - 12th
In this secondary mathematics learning exercise, students follow Lewis Carroll’s rules to solve Word Ladders.  The one page learning exercise contains two word ladder problems. Solutions are provided. 
Worksheet
Curated OER

Complex Analysis: Complex Exponential

For Students Higher Ed
In this complex exponential worksheet, students identify an entire function and explore how to show a function is analytic. This two-page worksheet contains four problems, as well as explanations and examples.
Lesson Plan
Curated OER

Gougu Rule or Pythagoras' Theorem

For Teachers 5th
Fifth graders explore Pythagoras' Theorem. They examine the pattern linking the length of the hypotenuse of a right angled triangle and the length of the other two sides. Students find an unknown side in right angled triangles.
Handout
Purple Math

Purplemath: Proving Trigonometric Identities

For Students 9th - 10th
An "identity" is a tautology, an equation or statement that is always true, no matter what. Proving an identity is very different in concept from solving an equation. This resource demonstrates some useful techniques for proving...
Unit Plan
CK-12 Foundation

Ck 12: Trigonometry: Proofs of Trigonometric Identities

For Students 10th - 12th Standards
[Free Registration/Login may be required to access all resource tools.] This lesson uses trigonometric identities to prove other identities.
Activity
Windstream

Ojk World of Math: Relationships Between the Functions

For Students 9th - 10th Standards
This tutorial discusses relationships among all the trig identities. Examples are given on how to apply them to simplify trig expressions and prove identities.
Handout
Windstream

Ojk's Precalculus Study Page: Sum and Difference Formulas for Tangent

For Students 9th - 10th Standards
This tutorial introduces the sum and differnce formulas for tangent, and gives several examples of problems to be solved as well as proving other identities. Assumes knowledge of the sum and difference formulas for sine and cosine.
Unknown Type
Windstream

Ojk's Precalculus Study Page: Trigonometry Sample Test

For Teachers 9th - 10th Standards
A practice test that covers proving trigonometric identities and solving advances trigonometric equations.
Activity
Texas Instruments

Texas Instruments: Basic Trigonometry Love or Leave It!!

For Teachers 9th - 10th
This activity has the teacher to create 3 triangles on Cabri Jr. on the TI-83 or TI-84. It will prove to students how trigonometry ratios are found. It will show to the students where the ratios are derived rather than just telling the...