The first two terms of an arithmetic sequence are a_1 = 2a1=2 and a_2 = 4a2=4. What is a_10a10, the tenth term?

1 Answer
Mar 17, 2018

color(indigo)(a_10 = 20a10=20

Explanation:

a_1 = 2, a_2 = 4a1=2,a2=4

Common Difference d = a_2 - a_1 = 4 - 2 = 2d=a2a1=42=2

nth term of an Arithmetic Sequence is given by the formula,

a_n = a_1 + (n-1) * dan=a1+(n1)d

Given a_1 = 2, n = 10a1=2,n=10 and we found d = 2d=2

:. color(indigo)(a_10) = 2 + (10-1)*2 = 2 + 18 color(indigo)(= 20