Sketch Graph f(x)=x^3 + 1/x | Math Homework Help

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SUMMARY

The discussion focuses on sketching the graph of the function f(x) = x^3 + 1/x. Participants suggest creating a table of values for initial graphing, while emphasizing the importance of finding stationary points using the first derivative, f'(x) = 0. To determine the nature of these points, the second derivative, f''(x), is utilized: if f''(x) is positive, the point is a minimum; if negative, it is a maximum. Additionally, analyzing the behavior of the function as x approaches ±∞ and 0 is crucial for a complete sketch.

PREREQUISITES
  • Understanding of basic calculus concepts, specifically derivatives.
  • Familiarity with graphing functions and interpreting graphs.
  • Knowledge of stationary points and their significance in graph analysis.
  • Ability to evaluate limits as x approaches infinity and zero.
NEXT STEPS
  • Learn how to compute and interpret the first and second derivatives of functions.
  • Study the behavior of rational functions as x approaches infinity and zero.
  • Explore graphing calculators or software for visualizing complex functions.
  • Investigate additional methods for sketching graphs, such as using asymptotes and intercepts.
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Students studying calculus, mathematics educators, and anyone seeking to improve their skills in graphing polynomial and rational functions.

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Homework Statement


Sketch the graph of f(x)=x^3 + 1/x


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The Attempt at a Solution


The only way I could think of doing this was by creating a table of values which I did, my graph came out decently close to the real thing (checked on graphing calculator), we did not learn how to use derivatives to find the increasing and decreasing part so how else would I go about doing this?
 
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Well at a stationary point...the first derivative is zero i.e. f'(x)=0.

That will allow you find any stationary point...to find whether it is maximum or minimum points

say you got [tex](x_1,f(x_1))[/tex] as a stationary point then you'd find [tex]f''(x_1)[/tex] and if it is +ve then that point is a min. but if it was -ve then it is a max.

also you should check what happens as [tex]x\rightarrow \pm\infty,0[/tex]
 
thanks
 

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