Formulaire trigo

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

$cos(\theta) = cos(-\theta)$

$sin(-\theta) = -sin(\theta)$

$cos(\pi - \theta) = -cos(\theta)$

$sin(\pi - \theta) = sin(\theta)$

$cos(\pi + \theta) = -cos(\theta)$

$sin(\pi + \theta) = -sin(\theta)$

$sin(\frac{\pi}{2} \pm \theta) = cos(\theta) \text{ et } cos(\frac{\pi}{2} \pm \theta) = \mp sin(\theta)$

$tan = \frac{sin}{cos}$

$\mathbb R \setminus \{\frac{\pi}{2} + k\pi\; k \in \mathbb Z\}$

$cos(a+b) = cos(a)cos(b) - sin(a)sin(b)$

$sin(a+b) = sin(a)cos(b) + sin(b)cos(a)$

$tan(a+b) = \frac{tan(a) + tan(b)}{1 - tan(a)tan(b)}$

$cos(a-b) = cos(a)cos(b) + sin(a)sin(b)$

$sin(a-b) = sin(a)cos(b) - sin(b)cos(a)$

$tan(a-b) = \frac{tan(a) - tan(b)}{1 - tan(a)tan(b)}$

$cos(2a) = cos^2(a)-sin^2(a) = 2cos^2(a) - 1 = 1 - 2sin^2(a)$

$sin(2a) = 2sin(a)cos(a)$

$tan(2a) = \frac{2tan(a)}{1-tan^2(a)}$

$cos(a)cos(b) = \frac{cos(a-b) + cos(a+b)}{2}$

$sin(a)sin(b) = \frac{cos(a-b) - cos(a+b)}{2}$

$sin(a)cos(b) = \frac{sin(a+b) + sin(a-b)}{2}$

$cos(\theta) = \frac{e^{i\theta} + e^{-i\theta}}{2}$

$sin(\theta) = \frac{e^{i\theta} - e^{-i\theta}}{2i}$