### Home > APCALC > Chapter 11 > Lesson 11.1.2 > Problem 11-26

11-26.

**Multiple Choice: **A

1 ft/sec

2 ft/sec

3 ft/sec

4 ft/sec

6 ft/sec

Sketch the situation. Your sketch should have similar right triangles.

If the child's distance from the light is and their shadow length is

*, then:*

The equation can be rewritten as

Now differentiate.

Now use the information given in the problem to solve for .