Question

What are the explicit equation and domain for an arithmetic sequence with a first term of 7 and a second term of 3?

Answer 1

an=a1+d(n-1)

a1=first term

d=common difference

n=which term

a1=7

a2=3

a2=3=7+d(2-1)

3=7+d(1)

3=7+d

-4=d

an=7-4(n-1)

expanded

an=7-4n+4

an=11-4n

domain is the numbers you can use for n (1,2,3,4,...)

the range is the output or the numbers you get in the sequence (7,3,-1,-5,...)

for the domain, we have to use numbers like 1,2,3,4,5

no 0

so we use natural numbers, that is the domain