11.1 Coordinates · Unit 11 Graphs

1 · Teaching slidesuse ← → keys

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2 · Key words

coordinatesA pair of numbers fixing a position: (x, y).

x-coordinateThe first number: how far across.

y-coordinateThe second number: how far up or down.

originThe point (0, 0) where the axes cross.

axisOne of the two number lines; the plural is axes.

quadrantOne of the four regions the axes divide the plane into.

midpointThe point exactly halfway between two others.

3 · Summary of the sectionrevise from this

Coordinates are written (x, y) — always across first, then up or down.
The origin is (0, 0), where the two axes cross.
The axes divide the plane into four quadrants, numbered anticlockwise from the top right.
Quadrant 1 (+, +), quadrant 2 (−, +), quadrant 3 (−, −), quadrant 4 (+, −).
A point with x = 0 lies on the y-axis; a point with y = 0 lies on the x-axis.
Points with the same y-coordinate lie on a horizontal line; same x-coordinate gives a vertical line.
The distance between two points on the same horizontal line is the difference in their x-coordinates.
The midpoint is found by averaging the x-coordinates and averaging the y-coordinates.

PDFPrintable worksheet All 67 questions, space to work PDFWorked answers Full solutions, not just the answer

Video lessons1 videos

Math Antics - Points, Lines, & Planes

American mathantics

The vocabulary of position, before coordinates are introduced.

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Coordinates