References

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Bogomolny, A. (2009). Trigonometry According to Ptolemy. Cut-The-Knot.org. https://www.cut-the-knot.org/triangle/PtolemysTrigonometry.shtml

E.Joyce, D. (2013). Ptolemy’s sum and difference formulas. Www2.Clarku.edu. https://www2.clarku.edu/faculty/djoyce/trig/ptolemy.html#:~:text=Ptolemy

Ghani, M. (2007, February 2). Sine, Cosine and the Measurement of the Earth. Muslim Heritage. https://muslimheritage.com/sine-cosine-measurement-earth/

Hunt, J. (2020). The Beginnings of Trigonometry. Rutgers.edu. https://sites.math.rutgers.edu/~cherlin/History/Papers2000/hunt.html

Merlet, J.-P. (n.d.). A NOTE ON THE HISTORY OF TRIGONOMETRIC FUNCTIONS AND SUBSTITUTIONS. Retrieved March 13, 2024, from https://www.math.stonybrook.edu/~tony/historyresources/HISTORY_OF_TRIGONOMETRIC_F.pdf

Proof of Compound Angle Identity sin(x+y). (2019). Www.youtube.com. https://www.youtube.com/watch?v=INAFQkpCwbQ

R.Jones, A. (2024, February 19). Ptolemy | Accomplishments, Biography, & Facts | Britannica. Www.britannica.com. https://britannica.com/biography/Ptolemy

Sack, H. (2022, June 10). Abu al-Wafa Buzjani – Negative Numbers and Trigonometry | SciHi Blog. http://scihi.org/abu-al-wafa-buzjani/

Sine, Cosine, and Ptolemy’s Theorem. (n.d.). Www.cut-The-Knot.org. Retrieved March 13, 2024, from https://www.cut-the-knot.org/proofs/sine_cosine.shtml