Point-Slope Form

• m is the slope of the line
• (x1, y1) is a point on the line.

Point-slope form is:

• Distribute m.
• Add/Subtract y1 to each side.

Example 3 Rewrite the equation in slope-intercept form. y - 5 = -2(x + 3)

• Find m.
• Choose one point.

Example 2 Write the equation of a line that passes through the points: (1,2) and (-2,-6)

• Given m.
• Given point.

Example 1 Write the equation for a line with a slope of 3 that passses through the point (4,5).

Point Slope Form

Unit 5 section 3

point-slope form

y-5 = 3(x-4)

• m = 3
• (4, 5) is a point on the line.

y-y1 = m(x-x1)

• m = 3
• (4, 5) is a point on the line.

Substitute

Identify

Example 1 Write the equation for a line with a slope of 3 that passses through the point (4,5).

• m is the slope of the line
• (x1, y1) is a point on the line.

Point-slope form is:

Recall

• Given m.
• Given point.

Example 2 Write the equation of a line that passes through the points: (1,2) and (-2,-6)

y-2 = 8 (x-1) 3

• m = 8

3

• (1, 2) is a point on the line.

y-y1 = m(x-x1)

• m = y2 -y1 = -6 - 2 = 8

x2 - x1 -2 - 1 3

• (1, 2) is a point on the line.

Substitute

Identify

• m is the slope of the line
• (x1, y1) is a point on the line.

Point-slope form is:

Recall

• Given m.
• Given point.

y - 5 = -2x + -6

y - 5 = -2x - 6 + 5 + 5

y = mx + b

Slope intercept form is:

y-y1 = m(x-x1)

Example 3 Rewrite the equation in slope-intercept form. y - 5 = -2(x + 3)

y = -2x-1

y - 5 = -2(x + 3)

• Distribute the m

• Add/Subtract y1 to both sides

Simplify

Identify

• m is the slope of the line
• (x1, y1) is a point on the line.
• b is the y-intercept

Point-slope form is:

Recall

• Given m.
• Given point.