Chapter 3.9, Problem 1PT

A right triangle has one leg with constant length 8 cm. The length of the other leg is decreasing at 3 cm/sec. The rate of change of the hypotenuse when the variable leg is 6 cm is:

1. a) $-\frac{9}{5}\text{cm/s}$
2. b) 3 cm/s
3. c) $-\frac{5}{3}\text{cm/s}$
4. d) $\frac{5}{3}\text{cm/s}$