Question

Describe when to use a series and when to use an equation.

For example, when would you use: f(x) = 3x+5
and when would you use: Height = 2 + 3n (where n is 1, 2, 3...)

Answer 1

A series is used only for n taking the values of natural numbers

But a function or an equation is used for all real values of x. It is not necessary that x should be a natural number.

Explanation:

The equation is used when domain is all real values

f(x) = 3x+5 is valid for all x real. x can take values as irrational also, negative or fractions.

But in a series, such as 2+3n, we have the restriction for domain n as only the set of all natural numbers

Here n cannot take negative or 0 or fractions or irrational numbers.

Thus the domain is the one which makes the difference of using an equation and a series.

A series is used only for n taking the values of natural numbers

But a function or an equation is used for all real values of x. It is not necessary that x should be a natural number.