Question

Which of the following is a function?
x=4
y= 3x
y=x
y= 2x-2

Answer 1

c

Explanation:

Answer 2

Functions:

• y = 3x
• y = x
• y = 2x - 2

Not a function:

• x = 4

Explanation:

A function is a relation between a set of inputs (x-values) and a set of possible outputs (y-values) with the property that each input is related to exactly one output.

The equation x = 4 is a vertical line, parallel to the y-axis. In this equation, a single value of x corresponds to an infinite number of possible y-values, which means it is not a function.

The equation y = 3x represents a linear relationship where y is equal to 3 times the value of x. It is a function because for each value of x, there is a unique value of y that corresponds to it.

The equation y = x represents a linear relationship where y is equal to x. It is a function because, for each value of x, there is a unique value of y.

The equation y = 2x - 2 represents a linear relationship where y is equal to 2 times the value of x minus 2. It is a function because, for each value of x, there is a unique value of y.

So, out of the given equations, the functions are:

• y = 3x
• y = x
• y = 2x - 2