Do Now 4 Find the equation of a line through the points (7, -2) and (3, -1).

Do Now: 4 Find the equation of a line through the points (7, -2) and (3, -1). 4 y = - ¼ x – ¼

2-6: Special Functions Direct Variation: A linear function in the form y = kx, where k 0 Constant: A linear function in the form y = b Identity: A linear function in the form y = x Absolute Value: A function in the form y = |mx + b| + c (m 0) Greatest Integer: A function in the form y = [x]

Direct Variation Function: A linear function in the form y = kx, where k –2–4–6x –2 –4 –6 y y=2x

Constant Function: A linear function in the form y = b. y = 3

Identity Function: A linear function in the form y = x. y=x

Absolute Value Function: A function in the form y = a|x - b| + c (m 0) y=|x - 2|-1 Example #1 The vertex, or minimum point, is (2, -1).

Absolute Value Function: A function of the form y = A|x - B| + C (m 0) y = -|x + 1| Example #2 The vertex, or maximum point, is (-1, 0).

Absolute Value Functions Graph y = |x| - 3 The vertex, or minimum point, is (0, -3).

Greatest Integer Function: A function in the form y = [x] 246–2–4–6x –2 –4 –6 y y=[x] Note: [x] means the greatest integer less than or equal to x. For example, the largest integer less than or equal to -3.5 is -4.

Greatest Integer Function: A function in the form y = [x] Graph y= [x] –2–4–6x –2 –4 –6 y