Directed Distance & Absolute Value Objective: To be able to find directed distances and solve absolute value inequalities. TS: Making Decisions after Reflection and Review Warm Up: Solve the following absolute value equation. |2x – 3| = 13
Distance Between Two Points. What is the distance between the two values of 10 and 2? What is the distance between the two values of -102 and 80? So the distance between two points x 1 and x 2 is |x 1 – x 2 | or |x 2 – x 1 | 8 182
Directed Distance The directed distance from a to b is b – a. Ex: Find the directed distance from 5 to – The directed distance from b to a is a – b. Ex: Find the directed distance from -10 to 5 5 – (-10) 15
Midpoint The midpoint between to values is a + b 2 Ex: Find the midpoint of the interval [1, 10]
Absolute Value Not true Is this statement true?
Absolute Value Think of absolute value as measuring a distance.
Absolute Value Absolute Value: The distance a number is from zero on a number line. It is always positive or zero.
Absolute Value ( ) The < sign indicates that the value is center around 0 and no more than 3 away.
Absolute Value ( ) The < sign indicates that the value is center around 2 and no more than 3 away. NOTICE: 2 is the midpoint of -1 and 5.
Absolute Value ] [ The > sign indicates that the value is diverging from points on either side of 0.
Absolute Value ] [ The > sign indicates that the value is diverging from points on either side of -3. NOTICE: -3 is the midpoint of -4 and -1.
Writing an Absolute Value 1)Write an absolute value inequality for the below intervals: (-∞, - 4]U[4, ∞) (-5, 5) (- ∞, 2)U(5, ∞) [-10, 20]
Absolute Value What does this statement mean? ( )
Absolute Value ] [ What does this statement mean?
Absolute Value
You Try Solve the following inequalities: 1) |2x|< 6 2) |3x+1|≥4 3) |25 – x|>20 Ans: (-3, 3) Ans: (-∞,-5/3] U [1,∞) Ans: (-∞,5) U (45,∞)
Conclusion Absolute value is the distance a number is from zero on a number line. Two equations are necessary to solve an absolute value equation. Two inequalities are necessary to solve an absolute value inequality.