Which function describes the arithmetic sequence shown

-1, 1, 3, 5, 7, 9, 11, 13,

f(n) = 2n - 3 describes the arithmetic sequence,

-1, 1, 3, 5, 7, 9, 11, 13,.......

Step-by-step explanation:

Function:

A function is like a machine that gives an output for a given input.

A function has an independent variable which is called the input of the function.

The output for a given input is called the dependent variable.

Here. 'n' is the independent variable

f(n) is the function dependent variable i.e function of n as an output.

For Arithmetic sequence

Where

= nth number of the sequence.

a₁ = First term

d = common difference = a₂ - a₁ = a₃ - a₂ = so on

For a function which describes Arithmetic sequence,

a₁ = -1

d = 1 - -1 =2

∴ f(n) = a₁ + (n -1 )d

substituting the values we get

∴ f(n) = -1 +(n-1)2

using distributive property

∴ f(n) = - 1 +  2n - 2

∴ f(n) = 2n - 3  ..........is the required function

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72