Standard diameter of golf ball = 42.67 mm
Maximum discrepancy accepted = 0.002 mm.
There are several ways to express that situation.
Calling x the diameter of any ball, these are the main two ways, one using the function absolute value and other without uisng it.
1) Without using the function absolute value:
42.67 mm - 0.02mm ≤ x ≤ 42.67 mm + 0.002 mm
42.65 mm ≤ x ≤ 42.69
2) Using the function absolute value
Subtract 42.67 mm on the three parts of the relation of above:
- 0.02 mm ≤ x - 42.67 mm ≤ 0.02
| x - 42.67mm| ≤ 0.02 mm