parallel vs. perpendicular

Front

What are parallel lines?

Back

Lines that never intersect and have the same slope.

Front

What are perpendicular lines?

Back

Lines that intersect at a right angle (90 degrees) and have slopes that are negative reciprocals of each other.

Front

What is the slope of a line parallel to y = 3x + 2?

Back

3

Front

What is the slope of a line perpendicular to y = 3x + 2?

Back

-1/3

Front

If two lines have slopes m1 and m2, when are they parallel?

Back

When m1 = m2.

Front

If two lines have slopes m1 and m2, when are they perpendicular?

Back

When m1 * m2 = -1.

Front

What is the slope of the line y = 2x - 7?

Back

2

Front

What is the slope of a line perpendicular to y = 2x - 7?

Back

-1/2

Front

If a line has a slope of -4, what is the slope of a line perpendicular to it?

Back

1/4

Front

What is the equation of a line parallel to y = -x + 5?

Back

y = -x + b (where b is any number).