Answer:
a₁, a₂, a₃, . . .
Explanation:
When we name something in Mathematics it is always advisable to number them as
.
Because the alphabets are only 26 in number we might run out of notations.
The simple logic behind the notion of
is that the numbers have no end and we can number as many variables we want using this logic.
In this problem, you can continue your notation from
so that you don't have to make a change in your figure.