# Example for Homework 1.1=

Your Rhea entry may discuss anything pertaining to the problem: an idea for an approach, a question, a comment on a supplemental relevant topic, etc.

For an example on using LaTeX, I have restated the problem below (for more help, see the Rhea LaTeX Manual)

- (a) Prove that $ 1 + x + x^2 + \ldots + x^{n-1} = \frac{1-x^n}{1-x} $ for $ x\neq1 $ and integer $ n\geq1 $.

- (b) What is $ 1 + 2x + 3x^2 + \ldots +nx^{n-1} $? (Hint: differentiate (a))