WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.
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Transcript of WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.
![Page 1: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/1.jpg)
WRITE EQUATIONS OF PARALLEL AND
PERPENDICULAR LINESNovember 20, 2008
Pages 319-321
![Page 2: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/2.jpg)
SOLUTION
1. Write an equation of the line that passes through (–3,–5) and is parallel to the line y = 3x – 1.
STEP 1
Identify the slope. The graph of the given equation has a slope of 3. So, the parallel line through (– 3, – 5) has a slope of 3.
![Page 3: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/3.jpg)
y = mx + b
– 5 = 3(– 3) + b
4 = b
Write slope-intercept form.
Substitute 3 for m, 3 for x, and 25 for y.
Solve for b.
STEP 3
Write an equation. Use y = mx + b.
y = 3x + 4 Substitute 3 for m and 4 for b.
STEP 2Find the y-intercept. Use the slope and the given point.
![Page 4: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/4.jpg)
SOLUTION
2. Determine which lines, if any, are parallel or perpendicular.
Line a: y = 5x – 3
Line b: x +5y = 2
Line c: –10y – 2x = 0
Find the slopes of the lines.
Line a: The equation is in slope-intercept form. The slope is 5.
![Page 5: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/5.jpg)
Line b: x + 5y = 2
5y = – x + 2
Line c: – 10y – 2x = 0
– 10y = 2x
y = – x15
xy =25
15 +
–
Write the equations for lines b and c in slope-intercept form.
![Page 6: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/6.jpg)
ANSWER
Lines b and c have slopes of – , so they are
parallel. Line a has a slope of 5, the negative reciprocal
of – , so it is perpendicular to lines b and c.
15
15
![Page 7: WRITE EQUATIONS OF PARALLEL AND PERPENDICULAR LINES November 20, 2008 Pages 319-321.](https://reader035.fdocuments.in/reader035/viewer/2022072015/56649ebb5503460f94bc3c2a/html5/thumbnails/7.jpg)
Assignment:
Pages 322-324 • 4 - 26 even• 28, 38, 39