الف) $\lim_{x \to \frac{\pi}{2}} \frac{1-\sin x}{\cos x}$

ب) $\lim_{x \to \frac{\pi}{4}} \frac{\cos(x+\frac{\pi}{4})}{\cos x - \sin x}$

پ) $\lim_{x \to 0} \frac{x^2}{|1-\cos x|}$

ت) $\lim_{x \to 0} \frac{2-2\cos 2x}{x \sin x}$

ث) $\lim_{x \to -\pi} \frac{\cos x + 1}{x+\pi}$

ج) $\lim_{x \to a} \frac{\sin x - \sin a}{x-a}$

چ) $\lim_{x \to \frac{\pi}{2}} \frac{\sin(x-\frac{\pi}{2})}{2x-2\pi}$

ح) $\lim_{x \to 1} \frac{2x-2\sqrt{x+1}}{x-1}$