$$\frac{1}{2^{x-1}}+\frac{1}{2^x}$$

$$\lim_{x\to1}\left(\ln x\tan\left(\frac{\pi}{2}x\right)\right)$$

$$\lim_{x\to\infty}\left(\frac{\ln\left(\sin\left(x\right)\right)}{x}\right)$$

$$\int\cos\frac{x}{7}dx$$

$$\frac{16x^2-25}{4-5}$$

$$5x^2-5x-30$$