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Min/max of function over sphere

  1. Jun 28, 2010 #1
    So, I seem to be drawing some blanks - my calc III is a little rusty.

    Find the max(2x+2y+z) and min(2x+y+z) on the surface x2+y2+z2=1

    At first I thought I would take partial derivatives, but none of them yield 0, so that's not going to work. Any suggestions would be mighty helpful because I will be dealing with problems a little harder than this, but if I can get this fundamental figured out, it will be extremely helpful.

  2. jcsd
  3. Jun 28, 2010 #2


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    Try LaGrange multipliers.
  4. Jun 28, 2010 #3
    That is exactly what I needed. Thank you so much for the hint! :)
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