Lesson 4-1 Identifying Linear Functions Obj: The student will be able to 1) Identify linear functions and linear equations 2) Graph linear functions that represent real-world situations and give their domain and range HWK: p 234 15-17 all, 18-40 even Vocab: 1) linear function 2) linear equation

Ex 1) Identify whether each graph represents a function. Explain Ex 1) Identify whether each graph represents a function. Explain. If so, is it a linear function?

For a function to be linear, look for a constant change in x-values and a constant change in y-values. Tell whether each set of ordered pairs satisfies a linear function. Explain. Ex 2) {(2,4), (5,3), (8,2), (11,1)}

Ex 3) {(-10,10), (-5,4), (0,2), (5,0)}

Standard Form of a Linear Equation: Ax + By = C where A, B and C are real numbers and A and B are not both 0 Things to notice about linear equations in standard form: x and y both have exponents of 1 x and y are not multiplied together x and y do not appear in denominators, exponents or radical signs

Tell whether each function is linear. If so, graph the function Ex 4) y = x + 3

Ex 5) y = x²

Ex 6) y = 2 𝑥

Ex 7) Sue rents a manicure station in a salon and pays the salon owner $5.50 for each manicure she gives. The amount Sue pays each day is given by f(x) = 5.50x where x is the number of manicures. Graph this function and give its domain and range.