1. At noon, ship A is 20 nautical miles due west of ship B. Ship A is sailing west at 23 knots and ship B is sailing north at 22 knots. How fast (in knots) is the distance between the ships changing at 6 PM?(Note: 1 knot is a speed of 1 nautical mile per hour.)

Below is the graph of the derivative of a function defined on the interval (0,8). You can click on the graph to see a larger version in a separate window.

2.

Refer to the graph to answer each of the following questions. For parts (A) and (B), use interval notation to report your answer. (If needed, you use U for the union symbol, and write None if there is no answer.)

(A) For what values of in (0,8) is increasing?(0,4)U(5,4) ?

(B) For what values of in (0,8) is concave down?(4,3) ?

(C) Find all values of in (0,8) is where has a local minimum?None ?

(D) Find all values of in (0,8) is where has an inflection point??4 ?

Help me please see if i did it right!! thanks.