Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Need help with review question on test tomorow

  1. Jun 10, 2004 #1
    need help please. tonight if possible. I need to find the largest area of a rectangle with base on the x-axis and upper corners touch the parabola with the equation y=12-x^2
    :smile: thanks :smile:
  2. jcsd
  3. Jun 10, 2004 #2


    User Avatar
    Science Advisor
    Homework Helper

    Well, you know the rectangle will be symmetrical about the y-axis. That means, if it touches the parabola at x = -a, it will touch at x = a as well. The rectangle will have an area of [itex]A = bh = (2x)(12 - x^2)[/itex]. Hopefully you see why this is. Now, it's simply a matter of finding the x value which gives a maximum for A, and I'm sure you know how to do this.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook