Download presentation

Presentation is loading. Please wait.

Published byKassidy Pocklington Modified over 2 years ago

1
**Write an equation given the slope and a point**

EXAMPLE 2 Write an equation given the slope and a point Write an equation of the line that passes through (5, 4) and has a slope of – 3. SOLUTION Because you know the slope and a point on the line, use point-slope form to write an equation of the line. Let (x1, y1) = (5, 4) and m = – 3. y – y1 = m(x – x1) Use point-slope form. y – 4 = – 3(x – 5) Substitute for m, x1, and y1. y – 4 = – 3x + 15 Distributive property y = – 3x + 19 Write in slope-intercept form.

2
EXAMPLE 3 Write equations of parallel or perpendicular lines Write an equation of the line that passes through (–2,3) and is (a) parallel to, and (b) perpendicular to, the line y = –4x + 1. SOLUTION a. The given line has a slope of m1 = –4. So, a line parallel to it has a slope of m2 = m1 = –4. You know the slope and a point on the line, so use the point-slope form with (x1, y1) = (– 2, 3) to write an equation of the line.

3
**Write equations of parallel or perpendicular lines**

EXAMPLE 3 Write equations of parallel or perpendicular lines y – y1 = m2(x – x1) Use point-slope form. y – 3 = – 4(x – (– 2)) Substitute for m2, x1, and y1. y – 3 = – 4(x + 2) Simplify. y – 3 = – 4x – 8 Distributive property y = – 4x – 5 Write in slope-intercept form.

4
**Write equations of parallel or perpendicular lines**

EXAMPLE 3 Write equations of parallel or perpendicular lines b. A line perpendicular to a line with slope m1 = – 4 has a slope of m2 = – = . Use point-slope form with (x1, y1) = (– 2, 3) 1 4 m1 y – y1 = m2(x – x1) Use point-slope form. y – 3 = (x – (– 2)) 1 4 Substitute for m2, x1, and y1. y – 3 = (x +2) 1 4 Simplify. y – 3 = x + 1 4 2 Distributive property y = x + 1 4 2 Write in slope-intercept form.

5
**GUIDED PRACTICE GUIDED PRACTICE for Examples 2 and 3**

4. Write an equation of the line that passes through (– 1, 6) and has a slope of 4. SOLUTION Because you know the slope and a point on the line, use the point-slope form to write an equation of the line. Let (x1, y1) = (–1, 6) and m = 4 y – y1 = m(x – x1) Use point-slope form. y – 6 = 4(x – (– 1)) Substitute for m, x1, and y1. y – 6 = 4x + 4 Distributive property y = 4x + 10 Write in slope-intercept form.

6
**GUIDED PRACTICE GUIDED PRACTICE for Examples 2 and 3**

5. Write an equation of the line that passes through (4, –2) and is (a) parallel to, and (b) perpendicular to, the line y = 3x – 1. SOLUTION The given line has a slope of m1 = 3. So, a line parallel to it has a slope of m2 = m1 = 3. You know the slope and a point on the line, so use the point - slope form with (x1, y1) = (4, – 2) to write an equation of the line. y – y1 = m2(x – x1) Use point-slope form. y – (– 2) = 3(x – 4) Substitute for m2, x1, and y1. y + 2 = (x – 4) Simplify. y + 2 = 3x – 12 Distributive property y = 3x – 14 Write in slope-intercept form.

7
**Use point - slope form with (x1, y1) = (4, – 2)**

GUIDED PRACTICE GUIDED PRACTICE for Examples 2 and 3 b. A line perpendicular to a line with slope m1 = 3 has a slope of m2 = – = – 1 1 3 m1 Use point - slope form with (x1, y1) = (4, – 2) y – y1 = m2(x – x1) Use point-slope form. y – (– 2) = – (x – 4) 1 3 Substitute for m2, x1, and y1. y + 2 = – (x – 4) 1 3 Simplify. 4 3 y + 2 = – x – 1 Distributive property y = – x – 1 3 2 Write in slope-intercept form.

Similar presentations

OK

Ms. Discepola’s JEOPARDY Unit 8. JEOPARDY – UNIT 8 Domain, Range, Relation FunctionsSlope & Intercepts Graphing Lines Not on the TEST 100 200 300 400.

Ms. Discepola’s JEOPARDY Unit 8. JEOPARDY – UNIT 8 Domain, Range, Relation FunctionsSlope & Intercepts Graphing Lines Not on the TEST 100 200 300 400.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on rational numbers for class 8 File type ppt on cybercrime news Ppt on hiroshima and nagasaki attack Ppt on content development for iptv Ppt on aerobics classes Ppt on weapons of mass destruction pictures Large intestine anatomy and physiology ppt on cells Ppt on reliance securities limited Ppt on interest rate swaps Ppt on recycling of waste