I'm very ashamed to ask this to the brains on this subreddit but I genuinely can't tell if I must be doing something wrong or if my graphing calculator is broken? It's
SIN function calculator and graph
Translating Sin and Cos functions with the TI-84 Plus - YouTube
DreamCalc Scientific Graphing Calculator
Trigonometric Function Graphs F(π)
3.7) Graphing Trig Functions on a TI 83 - YouTube
Solution 34771: Calculating Sine, Cosine, and Tangent Using the TI-84 Plus C Silver Edition Graphing Calculator.
A Trig Exercise Inspired by the Use of a Graphing Calculator.
Swift.org - Developer Spotlight: Porting Graphing Calculator from C++ to Swift