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Exercises

  1. Generate a surface plot and contour plot for the following function on the given domain:

    \begin{displaymath}f(x,y) = (x^2-y^2)e^{(-x^2-y^2)}, ~~ -3\leq x \leq 3, ~~ -3\leq y\leq 3 \end{displaymath}

    a)
    What does the contour plot look like in the regions where the surface plot has a steep incline? What does it look like where the surface plot is almost flat?
    b)
    What can you say about the surface plot in a region where the contour plot looks like a series of nested circles?

  2. Consider the following function from last week's lab

    \begin{displaymath}r(x,y) = \frac{2x+y-1}{1+x^2+2y^2} ~~ -3 \leq x \leq 5, ~~ -3 \leq y \leq 5 \end{displaymath}

    which represents the deviation, in inches, of last year's rainfall from the average annual rainfall in a certain area. Use a contour plot and shade in the region on your printout of this domain in which the deviation was between $-0.4$ inches and $-1.1$ inches.

  3. Consider the following function $\displaystyle f(x,y) = e^{(-x^2)} \cos(y)$ for $-2 \leq x \leq 2$ and $\frac{\pi}{2} \leq y \leq \frac{5\pi}{2}$ which looks like a deep valley with a mountain opposite it. Is it possible to find a path from the point $\displaystyle (1.5,\frac{\pi}{2},0)$ to $\displaystyle (-1.5,\frac{5\pi}{2},0)$ such that the value of $z$ is always between $-0.25$ and $0.25$? You do not have to find a formula for your path, but you must present convincing evidence that it exists. For example, you might want to sketch your path in by hand on an appropriate countour plot.


next up previous
Next: About this document ... Up: lab_template Previous: Background
Dina Solitro
2007-01-22