Maths (school) · Part 04
Graphs
Coordinates, straight lines, curves and real-life graphs.
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- CoordinatesA pair of numbers (x, y) that gives the exact position of a point on a grid. The first number is across, the second is up or down.
- GradientHow steep a line is. It is the amount the line goes up for every 1 step across.
- y = mx + cThe equation of a straight line. The number m is the gradient and c is where the line crosses the y-axis.
- Parallel and perpendicular linesParallel lines never meet and have the same gradient. Perpendicular lines meet at a right angle and their gradients multiply to give -1.
- Midpoint of a lineThe point exactly halfway along a line segment. Find it by averaging the x values and averaging the y values.
- Quadratic graphsThe graph of an equation with x^2 in it is a smooth U-shaped curve called a parabola.
- Cubic and reciprocal graphsA cubic graph, such as y = x^3, is an S-shape. A reciprocal graph, y = 1/x, has two separate curves that approach the axes without touching.
- Distance-time graphsA graph with time across and distance up. The gradient of the line is the speed.