WeBWorK Standalone Renderer

The contour plots for four different surfaces are given in the figure. Select the contour diagram for the function $f(x,y)$ that satisfies the following conditions at the point P.

1. $\displaystyle \frac{df}{dx}$ is positive and $\displaystyle \frac{df}{dy}$ is positive.

2. $\displaystyle \frac{df}{dx}$ is positive and $\displaystyle \frac{df}{dy}$ is negative.

3. $\displaystyle \frac{df}{dx}$ is negative and $\displaystyle \frac{df}{dy}$ is positive.

4. $\displaystyle \frac{df}{dx}$ is negative and $\displaystyle \frac{df}{dy}$ is negative.



A		B



C		D

(Click on a graph to enlarge it)

In order to get credit for this problem all answers must be correct.