Question

he graph of f(x) = StartRoot x EndRoot is reflected over the y-axis. Use the graphing calculator to graph this reflection. Which list contains three points that lie on the graph of the reflection?

(–81, 9), (–36, 6), (–1, 1)
(1, –1), (16, –4), (36, –6)
(–49, 7), (–18, 9), (–1, 1)
(1, –1), (4, –16), (5, –25)

Answer 1

Reflecting f(x) = sqrt(x) across the y-axis gives g(x) = f(-x) = sqrt(-x), so points are of form ( -a, sqrt(a) ) for a ≥ 0 (or x = -y^2, y ≥ 0).

Check choices:
- (–81, 9): 9 = sqrt(81) and x = -9^2 = -81 ✓
- (–36, 6): 6 = sqrt(36) and x = -6^2 = -36 ✓
- (–1, 1): 1 = sqrt(1) and x = -1^2 = -1 ✓

Therefore the first list is correct: (–81, 9), (–36, 6), (–1, 1).