Question

What are the explicit equation and domain for an arithmetic sequence with a first term of 5 and a second term of 2?
@jim_thompson5910 @myininaya @mathstudent55 @SolomonZelman @zepdrix @dan815 @wio @abb0t @iambatman

Answer 1

hint:

an = a1 + d(n-1)

an is the nth term
a1 is the first term
d is the common difference
n is the term number

Answer 2

so, an=5+3(n-1)

Answer 3

first term: a1 = 5
second term: a2 = 2

Answer 4

common difference:

(second term) - (first term) = 2 - 5 = -3

so d = -3 and NOT d = 3

Answer 5

ohhh! So an=5-3(n-1)

Answer 6

good

Answer 7

But is it integers when n>=1, or n>=0?

Answer 8

n starts at n = 1, so n >= 1

Answer 9

it's easiest to start at n = 1 to refer to the first term

n = 0 referring to the first term confuses things a bit

Answer 10

Thank you!!!!

Answer 11

np