<p>In the geometric section of the PR book it says
"The sum of the First n Terms of a geometric sequence is not a formula that is called upon very often, but it's good to know if you're taking math level 2"</p>
<p>and for the sum of an infinite geometric sequence it says "Every now and then, a question will ask you to figure out the sum of an infinite geometric sequence"</p>
<p>How often did you guys see these two questions on the test? should i memorize those equations?</p>