Graphing a Line Using Point and Slope (3.9.4)

Question 1

• Slope: rise/run, change in y / change in x = pitch

Answer 1

• Slope: rise/run, change in y / change in x = pitch

Question 2

• A positive slope indicates that a line rises when viewed from left to right.

Answer 2

• A positive slope indicates that a line rises when viewed from left to right.

Question 3

• A negative slope indicates that a line falls when viewed from left to right.

Answer 3

• A negative slope indicates that a line falls when viewed from left to right.

Question 4

When graphing a line using just one point and the slope, your first step is to locate the point.

Here, the point (1, 4) means you move from the origin,
(0, 0) one space to the right and four spaces up. Then place and label your point.

You can use the slope to determine a second point.

In this example, begin at (1, 4). From there, count up 3 and to the right 2. Place your second point. By definition, you have enough information now to draw a line. Just as a check you might count again to a third point to extend the line.

In this example, first locate the point (–1, –3).

The slope is negative, so count down to start instead of up. From (–1, –3), count down 4 and to the right 5 to locate your second point.

Finally, draw your line through the points.

For this line your starting point will be the origin, (0, 0).
From there, use your slope to count down 1, then to the right 1, and locate your second point.

Finally, draw the line.

Answer 4

When graphing a line using just one point and the slope, your first step is to locate the point.

Here, the point (1, 4) means you move from the origin,
(0, 0) one space to the right and four spaces up. Then place and label your point.

You can use the slope to determine a second point.

In this example, begin at (1, 4). From there, count up 3 and to the right 2. Place your second point. By definition, you have enough information now to draw a line. Just as a check you might count again to a third point to extend the line.

In this example, first locate the point (–1, –3).

The slope is negative, so count down to start instead of up. From (–1, –3), count down 4 and to the right 5 to locate your second point.

Finally, draw your line through the points.

For this line your starting point will be the origin, (0, 0).
From there, use your slope to count down 1, then to the right 1, and locate your second point.

Finally, draw the line.