Big Ideas Math Geometry, 2014
BI
Big Ideas Math Geometry, 2014 View details
Maintaining Mathematical Proficiency
Continue to next subchapter

Exercise 1 Page 63

What is the first term of the sequence? What is the common difference between terms? Use these values in the explicit equation for arithmetic sequences.

Equation: a_n=6n-3
Value of a_(50): 297

Practice makes perfect
Explicit equations for arithmetic sequences follow a specific format. a_n= a_1+( n-1) d In this form, a_1 is the first term in a given sequence, d is the common difference from one term to the next, and a_n is the nth term in the sequence. For this exercise, the first term is a_1= 3. Let's observe the other terms to determine the common difference d. 3+6 →9+6 →15+6 →21... By substituting these two values into the explicit equation and simplifying, we can find the formula for this sequence.
a_n=a_1+(n-1)d
a_n= 3+(n-1)( 6)
a_n=3+6n-6
a_n=6n-3
This equation can be used to find any term in the given sequence. To find a_(50), the 50th term in the sequence, we substitute 50 for n.
a_n=6n-3
a_(50)=6( 50)-3
a_(50)=300-3
a_(50)=297
The 50th term in the sequence is 297.