What you’ll learn
Graph y = mx + b.
Key idea
Slope is signed output change divided by input change; intercept is the output at zero input.
Slope and intercept are not interchangeable; reversed slope changes the trace direction.
Worked example
Enter the exact value or ordered values in the format requested below.
Read numerical slope of straight line L joining all marked points; x horizontal, y vertical.
Marked coordinates: L=(-2, 9); L=(-1, 6); L=(0, 3); L=(1, 0); L=(2, -3).
- L crosses the vertical axis at (0,3) and has signed rise -3 for run one.
- Equation y=-3x+3 matches both properties; points (0,3);(1,0) determine the full line.
Answer: -3
Quick Check
Relate the graph used in 'Graph y = mx + b' to an equation, table, transformation, or verbal description.
Connect full straight line L with its y=mx+b equation using signed slope and intercept, x horizontal, y vertical.
Marked coordinates: L=(2, 1); L=(1, 0); L=(0, -1); L=(-1, -2); L=(-2, -3).