Slopes of Lines Chapter 3 3 Finding Slope

Slopes of Lines Chapter 3 -3

Finding Slope of a Line

Remember! ¡ “Read” the line from left to right. l If it is going up, the slope is positive l If it is going down, the slope is negative ¡ Horizontal l Equation lines have a slope of 0. is y={y-intercept} ¡ Vertical lines have “no slope” or “undefined” l Equation is x={x-intercept}

Find the Slope of a Line Rise -8 2 Run

Find the Slope of a Line B. Find the slope of the line. Use the slope formula. Let (0, 4) be (x 1, y 1) and (0, – 3) be (x 2, y 2). which is undefined. Answer: undefined

Find the Slope of a Line C. Find the slope of the line. Answer:

Find the Slope of a Line D. Find the slope of the line. Answer: 0

A. Find the slope of the line. A. A B. B C. C D. D

B. Find the slope of the line. A. 0 A B. undefined B C. 7 C D. D

C. Find the slope of the line. A. A B. B C. – 2 C D. 2 D

D. Find the slope of the line. A. 0 A B. undefined B C. 3 C D. D

Slopes of // and lines // lines have equal slope ex: y = 2 x + 4 // y = 2 x – 6 Lines have opposite reciprocal slopes ex: y = 5 x – 3 y = x– 8

Determine Line Relationships A. Determine whether and perpendicular, or neither. are parallel, F(1, – 3), G(– 2, – 1), H(5, 0), J(6, 3) Find the slopes of and . Neither

Determine Line Relationships B. Determine whether and perpendicular, or neither. are parallel, F(4, 2), G(6, – 3), H(– 1, 5), J(– 3, 10) Answer: The slopes are the same, so and are parallel.

A. Find the slope of & Determine whether they are parallel, perpendicular, or neither. A(– 2, – 1), B(4, 5), C(6, 1), D(9, – 2) • The slopes are opposite reciprocals so they are

B. Find the slope of & Determine whether they are parallel, perpendicular, or neither. A(7, – 3), B(1, – 2), C(4, 0), D(– 3, 1) • Neither

Use Slope to Graph a Line Graph the line that contains Q(5, 1) and is parallel to with M(– 2, 4) and N(2, 1). First find the slope of . Slope formula Substitution Simplify.

Graph the line that contains Q(5, 1) and is parallel to with M(– 2, 4) and N(2, 1). Use Slope to Graph a Line The slopes of two parallel lines are the same. The slope of the line parallel to Graph the line. Start at (5, 1). Move down 3 units. Then move right 4 units. Label the point R. Draw . through Q(5, 1) is Answer: .

Graph the line that contains R(2, – 1) and is parallel to with O(1, 6) and P(– 3, 1). A. B. C. 1. 2. 3. 4. D. none of these A B C D

Homework: pg 160: # 1, 2, 6 – 20, 24 – 36 even, 48