Linear Function Lab: Change Slope and Intercept

Explore a linear function by changing slope, intercept, and input. Read its value, zero, and rise over run on a labeled grid.

Free, with no sign-up.

For High school students and adults reviewing the topic.

About 7 minutes.

How does it work?

  1. Set the slope and vertical intercept, then choose an input x.
  2. Compare the line with the marked input and output, or open a preset.
  3. Use the output table to check the challenges.

What will you get?

Connect the coefficients of a straight line with its graph and intercepts.

What does the model assume?

  • The rule is y = mx + b over all real inputs, using the school-algebra meaning of linear.
  • All coordinates are dimensionless and illustrative. The grid displays x from −10 to 10 and y from −60 to 60.
  • Rise is the output change for a run of one input unit. Changing the display scales does not change that ratio.
  • A horizontal line with a nonzero intercept has no x-intercept. If both slope and intercept are zero, every x is a zero.
  • An x-intercept outside the displayed window still belongs to the full line.

Which setup would you like to try?

What can you change?

Range: -5 to 5 .

Range: -10 to 10 .

Range: -10 to 10 .

What does the model predict?

QuantityValueUnit
Output y7.0000
x-intercept-0.5000
Zero statusOne x-intercept
Rise2.0000
Run1.0000
The line and its evaluated point
-10-50510-60-3003060Input xOutput y

Solid line: function. Circle: evaluated point. Dashed lines: coordinate guides.

Can you reach these targets?

Make the line pass through (1, 3) and (3, 7), then set x to 3.

  • Target: Slope m = 2 ; tolerance 0 .
  • Target: Vertical intercept b = 1 ; tolerance 0 .
  • Target: Input x = 3 ; tolerance 0 .
  • Target: Output y = 7 ; tolerance 0.001 .

Use a slope of −2 and make the line cross the horizontal axis at x = 4.

  • Target: Slope m = -2 ; tolerance 0 .
  • Target: x-intercept = 4 ; tolerance 0.001 .
Read the topic guide