Basic Trigonometry (Edexcel A-Level Mathematics): Flashcards

$\sin \theta = \frac{\text{Opposite}}{\text{Hypotenuse}}$

$\cos \theta = \frac{\text{Adjacent}}{\text{Hypotenuse}}$

$\tan \theta = \frac{\text{Opposite}}{\text{Adjacent}}$

$\csc \theta = 1 / \sin \theta = \text{Hypotenuse} / \text{Opposite}$

$\sec \theta = 1 / \cos \theta = \text{Hypotenuse} / \text{Adjacent}$

$\cot \theta = 1 / \tan \theta = \text{Adjacent} / \text{Opposite}$

A circle with radius $1$ centered at the origin.

$\sin^2 \theta + \cos^2 \theta = 1$

Radians = Degrees × $\pi$ / 180

$\sin 90° = 1$, $\cos 90° = 0$