Two points on a line cue a slope question: compare how far moves with how far moves. Enter the points in a Desmos table and fit a line; Desmos reports its slope. You can check that result by dividing the change in by the change in . Watch the negative sign in a coordinate when finding the horizontal change.
Hints
- Hint 1
In a Desmos table, each row holds one point: its -coordinate goes in the first column and its -coordinate in the second. Keep the coordinates in matching rows so Desmos plots the points you were given.
- Hint 2
A slope compares vertical change with horizontal change. Start at the first point and subtract its coordinates from the second point's coordinates. What happens to the horizontal change when you subtract a negative -coordinate?
Step-by-step
Plot the points and fit a line
Step 1Enter the two points
Put the points in a Desmos table, with each point's - and -coordinates in the same row. Desmos plots and . The second point is higher and farther right, so the line rises as increases.
- Step 2
Compare the coordinate changes
A slope is the change in divided by the change in . Subtract the first point's coordinates from the second point's coordinates:
Keep the point order the same for both changes. The line rises units for every units to the right.
- Step 3
Read the slope from Desmos
Type beneath the table. The tells Desmos to fit a line, is its slope, and is its -intercept, where it crosses the -axis. Under PARAMETERS, Desmos reports . That matches up for right, so the line's slope is . Choice A.