About Function Grapher
Plot linear (y = mx + c) and quadratic (y = ax² + bx + c) equations on an interactive grid. Drag the coefficient sliders to see the line or parabola change in real time, along with its key features.
How to Use
- Choose Linear or Quadratic.
- Adjust the coefficient sliders (m, c or a, b, c).
- Watch the graph update live and read the slope/intercepts or vertex/roots.
- Use the zoom slider to fit more of the curve.
Why Use This Tool?
- Accurate — built on precise, well-tested mathematical formulas.
- Instant — all calculations happen client-side for zero latency.
- Private — no data is sent to any server; your information stays on your device.
- Free — no sign-up, no limits, no hidden costs.
Frequently Asked Questions
How do I graph a linear equation?
A linear equation y = mx + c is a straight line: m is the slope (steepness) and c is where it crosses the y-axis. Set m and c and the line is drawn, with its x- and y-intercepts listed.
How do I find the roots of a quadratic?
The roots are where the parabola crosses the x-axis, found with the quadratic formula x = (−b ± √(b²−4ac)) / 2a. This grapher marks them in green and shows the values; if the discriminant (b²−4ac) is negative there are no real roots.
What is the vertex of a parabola?
The vertex is the turning point of the parabola (its minimum if a > 0, maximum if a < 0), located at x = −b/2a. It's marked in red on the graph and its coordinates are shown.
Is this a full graphing calculator?
It's a focused grapher for linear and quadratic functions, ideal for students learning algebra. For advanced multi-function graphing, a dedicated scientific graphing tool would be needed.