\(\mathrm{p(x) = |x - 2|}\)Which table gives three values of x and their corresponding values of p(x) for the given...
GMAT Advanced Math : (Adv_Math) Questions
Which table gives three values of x and their corresponding values of p(x) for the given function p?
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | -1 |
| 2 | 0 |
| 3 | 1 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 3 |
| 2 | 2 |
| 3 | 3 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
1. TRANSLATE the function notation into specific calculations
- Given: \(\mathrm{p(x) = |x - 2|}\)
- Need to find: \(\mathrm{p(1), p(2), and\ p(3)}\)
- This means substituting \(\mathrm{x = 1, x = 2, and\ x = 3}\) into the expression \(\mathrm{|x - 2|}\)
2. SIMPLIFY each calculation step-by-step
For \(\mathrm{p(1)}\):
- \(\mathrm{p(1) = |1 - 2|}\)
- \(\mathrm{= |-1|}\)
- \(\mathrm{= 1}\)
For \(\mathrm{p(2)}\):
- \(\mathrm{p(2) = |2 - 2|}\)
- \(\mathrm{= |0|}\)
- \(\mathrm{= 0}\)
For \(\mathrm{p(3)}\):
- \(\mathrm{p(3) = |3 - 2|}\)
- \(\mathrm{= |1|}\)
- \(\mathrm{= 1}\)
3. INFER which table matches your calculated values
- Looking for the table with: \(\mathrm{(1,1), (2,0), (3,1)}\)
- Table B shows exactly these value pairs
Answer: B
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak conceptual knowledge about absolute value: Students forget that absolute value always produces non-negative results.
They correctly compute \(\mathrm{1 - 2 = -1}\), but then write \(\mathrm{p(1) = -1}\) instead of \(\mathrm{p(1) = |-1| = 1}\). This fundamental misunderstanding of absolute value definition leads them to think negative outputs are possible.
This may lead them to select Choice A \(\mathrm{(-1, 0, 1)}\) since it matches their incorrect calculation for \(\mathrm{p(1)}\).
The Bottom Line:
This problem tests whether students truly understand that absolute value converts any negative result to positive, not just whether they can perform basic substitution and arithmetic.
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | -1 |
| 2 | 0 |
| 3 | 1 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 1 |
| 2 | 0 |
| 3 | 1 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 3 |
| 2 | 2 |
| 3 | 3 |
| x | \(\mathrm{p(x)}\) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |