How to Find a Geometric Formula Using Two Terms | Easy Method

In this video, you'll learn how to write an explicit formula for a geometric sequence when you're only given two terms! We'll go through three examples, demonstrating how to use the explicit formula a_n = a_1 * r^(n-1) and a system of equations to find the first term (a_1) and the common ratio (r). Here's what we'll cover: 00:00 Introduction to Writing Geometric Sequence Formulas from Two Terms 0:45 Understanding the Explicit Formula for Geometric Sequences 1:10 Method 1: Using Substitution to Solve for a_1 and r 2:50 Example 1: Given the 4th term is 10 and the 7th term is 5/4 6:00 Method 2: Dividing Equations to Solve for r 7:05 Example 2: Given the 4th term is 3/2 and the 2nd term is 2/3 (with two possible solutions!) 11:50 Example 3: Given the 2nd term is 1/7 and the 5th term is -27/7 By the end of this video, you'll be able to confidently write the formula for any geometric sequence given two of its terms! #GeometricSequence #ExplicitFormula #Algebra #MathTutorial #SequencesAndSeries #CommonRatio ➡️JOIN the channel as a CHANNEL MEMBER at the "ADDITIONAL VIDEOS" level to get access to my math video courses(Algebra 1, Algebra 2/College Algebra, Geometry, and PreCalculus), midterm & final exam reviews, ACT and SAT prep videos and more! (Over 390+ videos) https://www.youtube.com/channel/UClOR1BiPyOkkIAnv9Cmj4iw/join