Equations Graphing Lesson 4

Do Now 1. What is the slope of the line that passes through (3, 4) and (3, -1)? 2. Point Q lies on segment PR. If PQ is 2a – 5, QR is 2a + 7, and PR is 9a – 13, what is the measure of QR?

same slope opposite reciprocals Equations Notes Lines that are parallel have the ______ ______. Lines that are perpendicular have slopes that are __________ _____________. same slope opposite reciprocals

Equations Notes y = lines x = lines Have zero slope! y = 5 y = 2 Have undefined slope!

equation slope coefficient x term Equations Notes equation When looking at an __________ of a line, the _______ is the ____________ of the _________. slope coefficient x term What is the slope?? y = -½x + 4 y = 3x – 8 y = x

Class Example 1 Graph the line x = -2

Class Example 2 Which line below would be perpendicular to y = -2x + 3 ? A. y = 3 B. x = -2 C. y = ½x D. y = -½x

Class Example 3 Plot two points that would lie on the line perpendicular to line CD through point X.

Class Example 4 Line p contains the points (0, 2) and (-1, 5). Which of the following pairs of points define a line parallel to line p? A. (4, 3) and (5, 6) B. (-1, 0) and (2, 1) C. (9, -2) and (3 ,0) D. (3, -1) and (4 ,-4)

Class Example 5 Are these lines parallel, perpendicular, or neither (oblique)? y = -3x and y = 3x

Student Example 1 Graph the line y = 0

Student Example 2 Which line below would be parallel to x = 4 ? A. y = 4 B. x = -2 C. y = 4x D. y = -¼x

Student Example 3 Plot two points that would lie on the line parallel to line CD through point X.

Student Example 4 Line p contains the points (-2, 1) and (-2, 6). Which of the following pairs of points define a line perpendicular to line p? A. (4, 3) and (7, 6) B. (-1, 0) and (2, 2) C. (9, 0) and (3 ,0) D. (-3, -1) and (-3 ,-4)