$$\lim_{x \to \frac{\pi}{4}^-}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = 2$$
More at x→pi/4 from the left$$\lim_{x \to \frac{\pi}{4}^+}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = 2$$
$$\lim_{x \to \infty}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right)$$
More at x→oo$$\lim_{x \to 0^-}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = 0$$
More at x→0 from the left$$\lim_{x \to 0^+}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = 0$$
More at x→0 from the right$$\lim_{x \to 1^-}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = \frac{2 \sin{\left(1 \right)}}{\cos{\left(1 \right)}}$$
More at x→1 from the left$$\lim_{x \to 1^+}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right) = \frac{2 \sin{\left(1 \right)}}{\cos{\left(1 \right)}}$$
More at x→1 from the right$$\lim_{x \to -\infty}\left(\frac{2 \sin{\left(x \right)}}{\cos{\left(x \right)}}\right)$$
More at x→-oo