Miscellaneous

Some helpful algebraic generalities to review when stuck.

$$ax + b = x \cdot (a + \frac{b}{x})$$

$$\sqrt{a \cdot b} = \sqrt{a} \cdot \sqrt{b}$$

$$e = \lim \limits_{n \to \infty } \left( {1 + \frac{1}{n}} \right)^n$$

$$\lim \limits_{n \to \infty} \left( \frac{x^n}{n!} \right) = 0$$