| Resource | Title | APA Format |
| Journal | Tour of Simple Trigonometry Problem | Poon, K. (2012). Tour of a simple trigonometry problem. International Journal Of Mathematical Education In Science & Technology, 43(4), 449-461. doi:10.1080/0020739X.2011.622798 |
| Journal | Algebraic Trigonometry | Vaninsky, A. (2011). Algebraic trigonometry. International Journal Of Mathematical Education In Science & Technology, 42(3), 406-411. doi:10.1080/0020739X.2010.526307 |
| Journal | The unit circle approach to the construction of the sine and cosine functions and their inverses: An application of APOS theory | Martínez-Planell, R., & Cruz Delgado, A. (2016). The unit circle approach to the construction of the sine and cosine functions and their inverses: An application of APOS theory. Journal Of Mathematical Behavior, 43111-133. doi:10.1016/j.jmathb.2016.06.002 |
| Journal | Simple Expansion for Sine and Cosine | Withers, C. S., & Nadarajah, S. (2014). Simple expansions for sine and cosine. International Journal Of Mathematical Education In Science & Technology, 45(5), 738-741. doi:10.1080/0020739X.2013.868545 |
| Journal | On a Characteristic of Cosine Functions | Mei, Z., Peng, J., & Zhang, Y. (2014). On a characteristic of cosine functions. Semigroup Forum, 88(1), 221-226. doi:10.1007/s00233-013-9524-5 |
| Journal | On Periodicity of Trigonometric Functions and Connections with Elementary Number Theoretic Ideas. | Stupel, M. (2012). On periodicity of trigonometric functions and connections with elementary number theoretic ideas. Australian Senior Mathematics Journal, 26(1), 50-63. |
| Journal | Eulers Product Expansion for the Sine: An Elementary Proof | Ciaurri, Ó. (2015). Euler's Product Expansion for the Sine: An Elementary Proof. American Mathematical Monthly, 122(7), 693-695. doi:10.4169/amer.math.monthly.122.7.693 |
| Journal | A Generalization of the Identity cos π/3 = 1/2. | Packard, E., & Reitenbach, M. (2012). A Generalization of the Identity cos π/3 = 1/2. Mathematics Magazine, 85(2), 124-125. doi:10.4169/math.mag.85.2.124 |
| Journal | Proof Without Words: The Triple Angle Sine and Cosine Formulas | Alsina, C., & Nelsen, R. B. (2012). Proof Without Words: The Triple Angle Sine and Cosine Formulas. Mathematics Magazine, 85(1), 43. doi:10.4169/math.mag.85.1.43 |
| Journal | Disentangling a Triangle |
Kocik, J., & Solecki, A. (2009). Disentangling a Triangle. American Mathematical Monthly, 116(3), 228-237. |
| Journal | Alternative Proofs for Inequalities of some Trigonometric Functions | Guo, B., & Qi, F. (2008). Alternative proofs for inequalities of some trigonometric functions. International Journal Of Mathematical Education In Science & Technology, 39(3), 384-389. doi:10.1080/00207390701639516 |
| Book | Integrability Theorems for Trigonometric Transforms | Ralph Jr, P. (2012). Integrability theorems for trigonometric transforms (Vol. 38). Springer Science & Business Media. |
| Book | Some Remarkable Sine and Cosine Functions | Lindqvist, P. (1993). Some remarkable sine and cosine functions. Helsingin Teknillinen Korkeakoulu. Matematiikan Laitos. |
| Journal | The Calculus of Trigonometric Functions | Katz, V. J. (1987). The calculus of the trigonometric functions. Historia Mathematica, 14(4), 311-324. |
| Journal | Trigonometry from a different angle | Cavanagh, M. (2008). Trigonometry from a Different Angle. Australian Mathematics Teacher, 64(1), 25-30. |
| Video | Trigonometric Identities: How to derive/Remember them part 1 |
P. (2011, February 08). Trigonometric Identities: How to Derive / Remember Them - Part 1 of 3. Retrieved September 26, 2016, from https://www.youtube.com/watch?v=I4mcja8abDc |
| Video | Trigonometric Identities: How to derive/Remember them part 2 |
P. (2011, February 08). Trigonometric Identities: How to Derive / Remember Them - Part 2 of 3. Retrieved September 26, 2016, from https://www.youtube.com/watch?v=2wcNbjcL5_c
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| Video | Trigonometric Identities: How to derive/Remember them part 3 |
P. (2011, February 09). Trigonometric Identities: How to Derive / Remember Them - Part 3 of 3. Retrieved September 26, 2016, from https://www.youtube.com/watch?v=otfj1VDFfIs
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| Video | History of Trigonometry |
D. (2011, September 06). Algebra 2 11.01b - History of Trigonometry. Retrieved September 26, 2016, from https://www.youtube.com/watch?v=PhS_7M8jQbo
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| Video | Trigonometry Identity Review/Fun |
K. (2009, October 07). Trigonometry identity review/fun | Trig identities and examples | Trigonometry | Khan Academy. Retrieved September 26, 2016, from https://www.youtube.com/watch?v=a70-dYvDJZY
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| Website | Trigonometry from WolfRamAlpha |
Weisstein, E. W. (n.d.). Trigonometry. Retrieved September 26, 2016, from http://mathworld.wolfram.com/Trigonometry.html
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| Website | Proof of Trigonometric Identities and Formulas |
Bismarck, S. (n.d.). Trig Proofs. Retrieved September 26, 2016, from http://jwilson.coe.uga.edu/emt668/EMAT6680.2003.fall/Bismarck/6690 folder/trigproofs/triproofs.html |
| Website | Trig Identity Proofs |
MATH G11: Trigonometric Identity Proofs. (n.d.). Retrieved September 26, 2016, from https://www.unbounded.org/math/algebra-ii/module-2/topic-b/lesson-17 |
| Applet | Unit Circle Applet |
Interactive Unit Circle. (n.d.). Retrieved September 27, 2016, from https://www.mathsisfun.com/algebra/trig-interactive-unit-circle.html |
| Applet | Trigonometry Functions |
Trigonometry functions - introduction. (n.d.). Retrieved September 27, 2016, from http://www.mathopenref.com/trigfunctions.html |