Section 4 4 Find Slope Rate of Change

Section 4 -4 Find Slope & Rate of Change Objective: Students will solve for slope and determine rate of change Standard: F. IF. 6

Slope/Rate of Change: Change in y = Rise Change in x = Run Slope Formula: m = y 2 – y 1 x 2 – x 1 m stands for slope! run rise (x 1, y 1) (x 2, y 2)

Classification of Lines by Slope Positive slope: When m>0 rises from left to right. Negative slope: When m<0 falls from left to right.

Classification of Lines by Slope Zero slope: When (m=0) is horizontal HOY: Horizontal line zero slope runs through y-axis. A line with undefined slope (no slope) is vertical VUX: Vertical line undefined slope runs through x-axis.

Example 1 Find the slope of the line shown. run +8 rise +6 (-2, -2) (6, 4) m = rise run m = +6 = 3 +8 4 The slope of the line is ¾.

Example 2 Find the slope of the line shown. rise +3 (-3, 1) m = rise run (-3, -2) m = +3 = 3 0 0 The slope of the line is UNDEFINED– can’t have 0 in the denominator.

Example 3 Find the slope given the points. (x 2 , y 2) (x 1 , y 1) Find (-2 , 2) and (3 , 1) Use the slope formula m = y 2 - y 1 x 2 – x 1 Substitute m = (1 ) – ( 2 ) = -1 (3 ) – (-2) 5 The slope of the line is -1 5.

Example 4 Find the slope of the line given points. (x 1 , y 1) (x 2 , y 2) Find (-2 , -1) and (4 , -1) Use the slope formula m = y 2 - y 1 x 2 – x 1 Substitute m = (-1) – ( -1) = 0 (4 ) – (-2) 6 The slope of the line is 0.

Homework Section 4 -4 Pg. 239 -242 4 – 20, 36 -39