Consider this summation: Py

i$=$x

i

$2$

$.$

$($a$)$ Determine the equivalent closed$$form expression of this summation. $($In this context, $$closed$$form$$

means $$not a summation of y $$ x $+1$ terms.$)$ Include a short explanation of how you created the

expression.

$($b$)$ Prove that your answer to $($a$)$ is correct.