Parallel & Perpendicular Slope

Front

What does it mean for two lines to be parallel?

Back

Two lines are parallel if they have the same slope and will never intersect.

Front

What does it mean for two lines to be perpendicular?

Back

Two lines are perpendicular if the product of their slopes is -1.

Front

If the slope of a line is m, what is the slope of a line perpendicular to it?

Back

The slope of a line perpendicular to m is -1/m.

Front

What is the slope of a line parallel to a line with slope 2?

Back

The slope of a line parallel to a line with slope 2 is also 2.

Front

What are opposite reciprocals?

Back

Opposite reciprocals are two numbers whose product is -1; for example, if one slope is 3, the opposite reciprocal is -1/3.

Front

If two lines have slopes of 1/2 and -2, are they parallel, perpendicular, or neither?

Back

They are perpendicular because (1/2) * (-2) = -1.

Front

What is the slope of a line parallel to a line with slope -3/5?

Back

The slope of a line parallel to a line with slope -3/5 is also -3/5.

Front

How can you determine if two lines are parallel using their equations?

Back

If the coefficients of x in both equations are the same when in slope-intercept form (y = mx + b), the lines are parallel.

Front

What is the slope of a line perpendicular to a line with slope 0?

Back

The slope of a line perpendicular to a line with slope 0 (horizontal line) is undefined (vertical line).

Front

What is the relationship between the slopes of two lines that are neither parallel nor perpendicular?

Back

The slopes of two lines that are neither parallel nor perpendicular do not have a specific relationship; their product is not -1 and they are not equal.