Find the Taylor Series expansion of $\cosh x$ at the point $a=0$ and show that the remainder convergences to zero over $\left(-r,r\right)$ regardless the size of $r$.

For what values of rational $p$ and $q$ will $p\sqrt{2}+q\sqrt[3]{3}$ be rational? You may assume $\sqrt[3]{3}$ is irrational and of course $\sqrt{2}$ is irrational too. Recall though that the sum of two irrationals can be either rational or irrational. Hint: remember how to compare surds.

Calculate $ \lim\limits_{n \to  \infty } \sum \limits_{k=1}^n 4^{-k} $.

Calculate the limit $ \lim\limits_{n \to  \infty } \frac{\left(n^2+3\right)^\frac{1}{2}}{\left(n^2+2\right)^\frac{1}{3}} $.

Calculate the limit $ \lim\limits_{n \to  \infty } \cos \frac{1}{\sqrt{n}}} $.

For what values of $x$ will the following converge absolutely? $\sum\limits_{n=1}^\infty \frac{\left(3x-2\right)^n}{n}$

For what values of $x$ will the following converge absolutely? $\sum\limits_{n=1}^\infty n! x^n$

For what values of $x$ will the following converge absolutely? $\sum\limits_{n=1}^\infty 3^n \frac{ x^n }{ n! } $

For what values of $x$ will the following converge absolutely? $\sum\limits_{n=1}^\infty \left(-1\right)^{n-1} \frac{ x^n }{ n } $

Given that $0 < a < b$ prove $a < \sqrt{ab} < b$ and $ \sqrt{ab} < \frac{a+b}{2}$