\(\begin{aligned}\href{/posts/cosine}{\cos}(\alpha) &= \frac{\text{adjacent}}{\text{hypotenuse}} \\ &= \frac{\href{/posts/sine}{\sin}(\alpha)}{\href{/posts/tangent}{\tan}(\alpha)}\end{aligned}\)
Also see Sine and Tangent (Trigonometry); Trigonometry.
Graph of \(\href{/posts/cosine}{\cos}\)
Bibliography
“Sine and Cosine.” 2022. Wikipedia, August. https://en.wikipedia.org/w/index.php?title=Sine_and_cosine&oldid=1103922899.