Solving an Absolute-Value Inequality Recall that x is the distance between x and 0. If x 8, then any number between 8 and 8 is a solution of the inequality. 8 7 6 5 4 3 2 Recall that | x | is the distance between x and 0. If | x | 8, then any number between 8 and 8 is a solution of the inequality.
Solve | x 4 | < 3 Solving an Absolute-Value Inequality x 4 IS POSITIVE x 4 IS NEGATIVE | x 4 | 3 x 4 3 x 7 | x 4 | 3 x 4 3 x 1 Reverse inequality symbol. This can be written as 1 x 7. The solution is all real numbers greater than 1 and less than 7.
2x 1 9 | 2x 1 | 3 6 | 2x 1 | 9 2x 10 2x + 1 IS NEGATIVE x 5 Solve | 2x 1 | 3 6 and graph the solution. | 2x 1 | 3 6 | 2x 1 | 9 2x 1 +9 2x 8 2x + 1 IS POSITIVE x 4 Solving an Absolute-Value Inequality Reverse inequality symbol. | 2x 1 | 3 6 | 2x 1 | 9 2x 1 +9 x 4 2x 8 | 2x 1 | 3 6 | 2x 1 | 9 2x 1 9 2x 10 x 5 2x + 1 IS POSITIVE 2x + 1 IS NEGATIVE 6 5 4 3 2 The solution is all real numbers greater than or equal to 4 or less than or equal to 5. This can be written as the compound inequality x 5 or x 4. 5
Writing an Absolute-Value Inequality You work in the quality control department of a manufacturing company. The diameter of a drill bit must be between 0.62 and 0.63 inch. Write an absolute-value inequality to represent this requirement. a. Does a bit with a diameter of inch meet the requirement? b.
Writing an Absolute-Value Inequality The diameter of a drill bit must be between 0.62 and 0.63 inch. a. Write an absolute-value inequality to represent this requirement. Let d represent the diameter (in inches) of the drill bit. Write a compound inequality d 0.63 Find the halfway point Subtract from each part of the compound inequality d 0.63 d Rewrite as an absolute-value inequality. | d | This inequality can be read as “the actual diameter must differ from inch by no more than inch.”
The diameter of a drill bit must be between 0.62 and 0.63 inch. b. Does a bit with a diameter of meet the requirement? Writing an Absolute-Value Inequality | d | | | | | Because 0.005, the bit does meet the requirement 0.005