Structure question 2 doc

M = (

–3

2

+ 1

,

5 +

2

(–4)

)

M = (–

2

2

,

1

2

)

M = (–1,

1

2

)

Note: There is no such thing as the midpoint of a line, as lines are infinite in length.

SLOPE

The slope of a line (or line segment) is a numerical value given to show how steep a line is. A line or segment can

have one of four types of slope:

■ A line with a positive slope increases from the bottom left to the upper right on a graph.

■ A line with a negative slope decreases from the upper left to the bottom right on a graph.

■ A horizontal line is said to have a zero slope.

■ A vertical line is said to have no slope (undefined).

■ Parallel lines have equal slopes.

■ Perpendicular lines have slopes that are negative reciprocals of each other.

Positive slope

y

1

4

3

2

–5

–1

–2

–3

–4

–5 –4 –3 –2 –1 1 2 3 4 5

x

5

y

1

4

3

2

–5

–1

–2

–3

–4

–5 –4 –3 –2 –1 1 2 3 4 5

x

5

y

1

4

2

–5

–1

–2

–3

–4

–5 –4 –3 –2 –1 1 2 3 4 5

x

5

y

1

4

3

2

–5

–1

–2

–3

–4

–5 –4 –3 –2 –1 1 2 4 5

x

5

3

3

Negative slope

Zero slope Undefined (no) slope

–THEA MATH REVIEW–

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