Explain why vertical lines are a special case in the definition of parallel lines.

A vertical line has an infinite or undefined slope since the denominator is zero.

Step-by-step explanation:

Parallel lines by definition refers to lines that never intersect or meet since they have identical slopes. The slope of line is defined as;

(change in y)/(change in x)

For a vertical line, the y values are changing while the x values remain constant. The slope of this line will thus have a zero value in the denominator implying that its slope will not defined or will be infinity.

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

well the answer to that is xoxoxo

step-by-step explanation: