Question

The number of unread emails in Bryan’s account is 100. This number grows by 15 unread emails a day. The function N(t)=100+15t represents the relation between the number of unread emails, N, and the time, t, measured in days.

Answer 1

Independent variable = t

Dependent variable = N

Explanation:

Given that the function N(t)=100+15t represents the relation between the number of unread emails, N, and the time, t, measured in days

The independent variable is an input which can be controlled. In the function

N(t)=100+15t

The independent variable is t

While the dependent variable is the output of a function when independent variable has been substituted.

In the function N(t)=100+15t

The number of unread messages depends on the number of time t measured in days as the number of unread messages N is a function of t.

Therefore, the independent variable is N.