Writing the equation of a line from a graph, counting the slope

Front

What is the equation of a horizontal line?

Back

y = b, where b is the y-intercept.

Front

What is the equation of a vertical line?

Back

x = a, where a is the x-intercept.

Front

How do you calculate the slope (m) of a line?

Back

m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line.

Tags

CCSS.8.EE.B.5

Front

What does a positive slope indicate about a line?

Back

The line rises from left to right.

Tags

CCSS.8.EE.B.5

Front

What does a negative slope indicate about a line?

Back

The line falls from left to right.

Tags

CCSS.8.EE.B.5

Front

What does a slope of zero indicate?

Back

The line is horizontal.

Tags

CCSS.8.EE.B.5

Front

What does an undefined slope indicate?

Back

The line is vertical.

Tags

CCSS.8.EE.B.5

Front

What is the slope-intercept form of a line?

Back

y = mx + b, where m is the slope and b is the y-intercept.

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

Front

What is the point-slope form of a line?

Back

y - y1 = m(x - x1), where (x1, y1) is a point on the line.

Front

How do you find the y-intercept from a graph?

Back

The y-intercept is the point where the line crosses the y-axis.