Calculus 1: Finding the maxima and minima of the function 1-x^(2/3)

dez_cole
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Homework Statement



I am given the problem "A function is defined by f(x) = 1-x^(2/3).

a. find the minima and maxima of the function. State whether they are relative or absolute.

b. graph the function."


Homework Equations



I found the derivative and set it equal to zero. y' = -(2/3)x^(-1/3), -(2/3)x^(-1/3) = 0


The Attempt at a Solution



Now I really have little idea of where to go from here because I am left with a few questions. If i set the derivative equal to zero and set x to be zero would the statement "-(2/3)0^(-1/3) = 0" be true or would I essentially be dividing by zero because x^(-1/3) = 1/ \sqrt[3]{x}? Now if this is a spot where the velocity is zero would you consider it a max, a min, or would it be irrelevant to my answer because you can't quite classify it either way. I think it is simply an interesting value on the graph, but is neither a maximum or minimum relative or absolute, and this graph has no maxes or mins.

Thanks for your help. I really appreciate it.
 
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Sketch a graph. You are correct that the derivative at x=0 doesn't exist. It still might be a max or a min. It's an "interesting point" as you put it.
 
Thanks again.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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