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Daily Check. Graph the following equations. Math II. UNIT QUESTION: How are absolute value equations similar to piecewise functions? Standard: MM2A1 Today’s Question: How are absolute value equations similar to piecewise functions? Standard: MM2A1.a,b.
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Daily Check Graph the following equations.
Math II UNIT QUESTION: How are absolute value equations similar to piecewise functions? Standard: MM2A1 Today’s Question: How are absolute value equations similar to piecewise functions? Standard: MM2A1.a,b
Absolute Value as Piecewise Functions Section 2.5
Piecewise Functions • Piecewise functions are functions that can be represented by more than one equation, with each equation corresponding to a different part of the domain. • Piecewise functions do not always have to be line segments. The “pieces” could be pieces of any type of graph. • This type of function is often used to represent real-life problems like ticket prices.
Example x + 1, if x < 1 2, if 1 ≤ x ≤ 3 (x-3)2 + 2, if x > 3 f (x) =
Absolute Value as Piecewise • We usually write an absolute value function as f (x)= x , but since absolute value is a measure of distance and distance is always positive, it also can be written as follows: -x, if x < 0 x, if x ≥ 0 f (x) =
Writing Abs. Value as Piecewise • For I x – h I ≥ 0, simplify the equation given by distributing and combining like terms. • For I x – h I < 0, substitute –(x – h) in place of I x - h I. Then, simplify.
Example • Write y = 2 Ix – 4I – 10 as a piecewise function. • For (x-4) ≥ 0 2(x – 4) – 10 = 2x – 8 – 10 = 2x – 18 (when x ≥ 4) • For (x-4) < 0 2[-(x-4)] – 10 = 2(-x + 4) – 10 = -2x + 8 – 10 = -2x – 2 (when x < 4))
Graphs of Both y=-2x-2 y=2x-18
Writing Abs. Value as Piecewise • Using a graph
Writing Abs. Value as Piecewise • Try this one...
Practice • Worksheet
Homework • Worksheet