Domain of x^(1/3) +x^(4/3): Why Negative Values Not Allowed?

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SUMMARY

The discussion centers on the domain restrictions of the function x^(1/3) + x^(4/3), specifically addressing why negative values are not included in the graphing of this function. Users noted that standard function graphers and calculators return errors for negative inputs due to the interpretation of fractional exponents. The consensus is that while negative numbers can be raised to the power of 4/3, many graphing tools misinterpret the fractional exponent, leading to incorrect domain representations. A recommended tool for accurate graphing is the online program available at Padowan.dk.

PREREQUISITES
  • Understanding of fractional exponents and their implications in real numbers.
  • Familiarity with graphing functions and the limitations of various graphing tools.
  • Basic knowledge of limits and derivatives in calculus.
  • Experience with online graphing calculators and their functionalities.
NEXT STEPS
  • Research the properties of fractional exponents in real number systems.
  • Explore alternative graphing tools, specifically Padowan.dk, for complex functions.
  • Study the mathematical principles behind domain restrictions in polynomial functions.
  • Learn about the differences in handling negative bases across various mathematical software.
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Students studying calculus, educators teaching functions and graphing, and anyone interested in understanding the behavior of polynomial functions with fractional exponents.

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Homework Statement



Graph x^(1/3) +x^(4/3)


Homework Equations



Limits, derivatives, etc.

The Attempt at a Solution



Hi guys, I was attempting this problem and then verifying it using a function grapher online. I noticed that all of the function graphers do not plot the function for avalues of x less than 0, and my calculator also gives an error when attempting a negative number to the power of 4/3. I would assume you can raise a negative number to the power of 4/3, so why does the calculator give an error and the function graphers so that negative x is outside the domain? Any ideas?
 
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Ah yes. Well, most of the function graphers treat 1/3 as 0.333333333... So they don't consider 1/3 as a fraction, but as a real number instead. But a negative number exponent a general real number does not have to exist. It only exists if this real number is a fraction. But function graphers fail to see that it IS a fraction. So it's really because function graphers are stupid...


I would suggest following (free) program which circumvented the problem and which would graph your function correctly: http://www.padowan.dk/graph/
 
That's much better, thanks for the help.
 

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