CÔNG THỨC LƯỢNG GIÁC 1

$$\sin^2x-\cos^2x=1$$

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

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

$$\cos^2x=\sin^2x-1$$

$$1+\cos^2x=\frac{1}{\tan^2x}$$

$$1-\cos^2x=\frac{1}{\tan^2x}$$

$$1+\tan^2x=\frac{1}{\cos^2x}$$

$$1-\tan^2x=\frac{1}{\cos^2x}$$

$$\frac{\sin x}{\cos x}$$  

$$\frac{\sin a}{\cos a}$$  

$$\frac{\sin2x}{\cos2x}$$  

$$\frac{\sin2a}{\cos2a}$$  

$$1$$  

$$\frac{1}{2}$$  

$$\frac{\sqrt{3}}{2}$$  

$$\frac{-\sqrt{3}}{2}$$  

$$\frac{\sqrt{6}+\sqrt{2}}{4}$$  

$$\frac{\sqrt{6}-\sqrt{2}}{4}$$  

$$\frac{\sqrt{2}}{2}$$  

$$\frac{\sqrt{3}}{2}$$  

$$\frac{\pi}{6}$$  

$$\frac{-\pi}{6}$$  

$$\frac{\pi}{3}$$  

$$\frac{-\pi}{3}$$  

- x

$$\frac{\pi}{2}-x$$  

$$\pi-x$$  

$$\pi+x$$  

$$-x$$  

$$\pi-x$$  

$$\frac{\pi}{2}-x$$  

$$\pi+x$$  

x

- 2x

$$\frac{\pi}{2}-x$$

$$\frac{\pi}{2}-2x$$

$$\sin\ x$$  

$$-\sin\ x$$  

$$\cos\ x$$  

$$-\cos x$$  

$$-\sin\ x$$  

$$\sin\ x$$  

$$\cos\ x$$  

$$-\cos x$$  

$$\sin x$$  

$$\cos\ x$$  

$$\tan\ x$$  

$$\cot\ x$$  

$$\cos\ 2x$$  

$$\cos\ \alpha$$  

$$\sin\ \alpha$$  

$$\sin2\alpha$$  

$$-\sin x+\cos x+\tan x$$  

$$\sin x-\cos x+\cot x$$  

$$-\sin x+\cos x+\cot x$$  

$$-\sin x-\cos x+\cot x$$