A 13 ft ladder leaning against a wall begins to slide. How fast is the top of the ladder sliding down the wall at the instant of time when the bottom of the ladder is 5 ft from the wall and sliding away from the wall at the rate of 4 ft/sec? Hint: Refer to the accompanying figure. By the Pythagorean Theorem, x 2 + y 2 = 169. Find dy dt when x = 5 and dx dt = 4. (Round your answer to two decimal places and do not forget your