Pyetja
Vërteto identitetet e mëposhtme.
- $\frac{\cos 2A}{\cos A + \sin A} \equiv \cos A - \sin A$
- $\frac{\sin B}{\sin A} - \frac{\cos B}{\cos A} = 2 \operatorname{cosec} 2A \sin (B - A)$
- $\frac{1 - \cos 2\theta}{\sin 2\theta} \equiv \tan \theta$
- $\frac{\sec^2 \theta}{1 - \tan^2 \theta} = \sec 2\theta$
- $2(\sin^3 \theta \cos \theta + \cos^3 \theta \sin \theta) = \sin 2\theta$
- $\frac{\sin 3\theta}{\sin \theta} - \frac{\cos 3\theta}{\cos \theta} = 2$
- $\operatorname{cosec} \theta - 2 \cot 2\theta \cos \theta = 2 \sin \theta$
- $\frac{\sec \theta - 1}{\sec \theta + 1} = \tan^2 \frac{\theta}{2}$
- $\tan\left(\frac{\pi}{4} - x\right) \equiv \frac{1 - \sin 2x}{\cos 2x}$
