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1.7 Warm Up 1. Find the slope and y-intercept: a. y = 2x – 5 b. 9x + y = 8 c. 8y – 2x = 4 2. Graph the equation: a. y = -2/3 x + 1 b. y = 4/3 x - 5 1.7 Graphing Linear Functions Vocabulary • Function notation: f(x) read f of x – Linear function notation: f(x) = mx + b – It is the same as saying “y” • Family of functions: have same characteristics • Parent linear function: most basic f(x) = x EXAMPLE 1 Standardized Test Practice EXAMPLE 2 Find an x-value For the function f(x) = 2x – 10, find the value of x so that f(x) = 6. EXAMPLE 4 Compare graphs with the graph f (x) = x Graph the function. Compare the graph with the graph of f (x) = x. a. g(x) = x + 3 SOLUTION Because the graphs of g and f have the same slope, m = 1, the lines are parallel. Also, the y- intercept of the graph of g is 3 more than the yintercept of the graph of f. EXAMPLE 4 Compare graphs with the graph f (x) = x b. h(x) = 2x SOLUTION The graph is a vertical stretch of the parent function by a scale factor of 2. Write an equation from4 a graph for Example GUIDED PRACTICE 3. Graph h(x) = – 3x. Compare the graph with the graph of f (x) = x. SOLUTION The graph is a vertical stretch of the parent function by a scale factor of 3 and a reflection over the x-axis. • Compare the functions to the graph of f(x) = x. a. f(x) = 5x b. f(x) = -1/2 x c. f(x) = x – 2 d. f(x) = x + 8 Matching • Match the function w/ its description in relation to the graph of f(x)=x. 1. g(x) = 4x 2. g(x) = x + 4 3. g(x) = x – 4 a. Vertical shift of 4 units up b. Vertical shift of 4 units down c. Vertical stretch w/ a scale factor of 4 • • • • • • • • • • y = -2x – 1 y = 1/3 x + 1 y = 4/3 x – 4 y = -3x y = -2x + 5 y = 1/7 x – 3 y = 9x y = -8x + 3 y = 1/5 x + 3 y = -1/2 x - 2 • • • • • • • • • y=½x–9 y = -1/6 x y = -4x – 4 y = -1/5 x – 8 y = 6x + 6 y = 5x – 2 y = -3x + 2 y = -1/9 x – 2 y = 8/7x + 4