Equations of Parallel and Perpendicular Lines

Front

What are parallel lines?

Back

Parallel lines are lines in a plane that never meet. They have the same slope but different y-intercepts.

Front

What are perpendicular lines?

Back

Perpendicular lines are lines that intersect at a right angle (90 degrees). The slopes of perpendicular lines are negative reciprocals of each other.

Front

How do you determine if two lines are parallel from their equations?

Back

Two lines are parallel if their slopes are equal.

Front

How do you determine if two lines are perpendicular from their equations?

Back

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

Front

What is the slope of the line y = (-1/2)x + 1?

Back

The slope is -1/2.

Front

What is the slope of the line y = (1/2)x - 5?

Back

The slope is 1/2.

Front

Are the lines y = (-1/2)x + 1 and y = (1/2)x - 5 parallel?

Back

No, they are not parallel because their slopes are not equal.

Front

What is the slope of the line y = 6x + 2?

Back

The slope is 6.

Front

What is the slope of the line y = -6x + 2?

Back

The slope is -6.

Front

Are the lines y = 6x + 2 and y = -6x + 2 perpendicular?

Back

Yes, they are perpendicular because the product of their slopes (6 * -6) is -36, not -1.