Determine if the relation y=4x−1

is a function by first graphing the relation, then applying the vertical line test. Enter 1 if the relation is a function. Enter 2 if the relation is not a function.

1 answer

To determine if the relation \( y = 4x - 1 \) is a function, we can follow these steps:

  1. Understanding the relation: This is a linear equation in the form of \( y = mx + b \), where \( m = 4 \) (the slope) and \( b = -1 \) (the y-intercept).

  2. Graphing the relation: This line can be graphed by plotting the y-intercept at \( -1 \) (which is the point \( (0, -1) \)) and then using the slope to find another point. From the y-intercept, you can go up 4 units and right 1 unit to find another point at \( (1, 3) \). Connecting these points gives you a straight line.

  3. Applying the vertical line test: The vertical line test states that if a vertical line crosses the graph of a relation at more than one point, then the relation is not a function.

Since a straight line (like the one described by \( y = 4x - 1 \)) can be intersected by any vertical line at most once, we conclude that this relation passes the vertical line test.

Therefore, \( y = 4x - 1 \) is a function.

So, the answer is: 1 (indicating that the relation is a function).