Graphing a*b^0.3=constant: Which Variable Goes on the Y-Axis?

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Discussion Overview

The discussion revolves around graphing the equation a*b0.3 = constant, focusing on which variable should be placed on the y-axis and which on the x-axis. Participants explore the implications of their choices on the graph's shape and behavior, discussing both theoretical and practical aspects of graphing this equation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant seeks guidance on whether to use b or b0.3 for the y-axis, indicating confusion about the graph's shape.
  • Another participant describes their method of plotting b on the horizontal axis and calculating corresponding a values, noting a nonlinear curve with a negative slope that appears almost linear between certain b values.
  • Several participants share links to graphing tools, identifying the graph as a hyperbola and discussing the scaling effect of the constants involved.
  • Questions arise about the categorization of online graphing services, with references to WolframAlpha and Desmos as useful tools for quick calculations.
  • A participant introduces the idea of using logarithmic axes for graphing, suggesting it can simplify the representation of the relationship between variables.
  • Another participant expresses confusion about the linearization process, questioning how the original and transformed graphs relate to each other.

Areas of Agreement / Disagreement

Participants express differing views on the appropriate axes for the graph and the implications of using logarithmic transformations. There is no consensus on the best approach or the interpretation of the graph's shape.

Contextual Notes

Some discussions involve assumptions about the behavior of the graph under different transformations and the implications of using various graphing tools. The relationship between the original equation and its logarithmic form is also noted as a point of potential confusion.

Who May Find This Useful

This discussion may be useful for individuals interested in graphing mathematical equations, particularly in the context of physics or engineering applications, as well as those exploring the use of online graphing tools.

mech-eng
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I would like to sketch the graph of equation a*b^0.3=constant for a and b are positive real numbers. How do I start?

Which one should be as y-axis, and which one be x-axis. This only affects the shape of the graph. The confusing part for me is that should I use b itself or b^03 as an axis?

Thank you.
 
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I put b in the horizontal axis and give it values 10, 15, 20, 25, 30, 35, 40, 45 and calculated b^0.3 values. I choose constant=100 and then dividing 100/b^0.3 values I calculate a values. The graph is a curve with negative slope, nonlinear shape but it is like it behaves almost linear between b=20 and b=35 values.

Thank you.
 
fresh_42 said:
Here's the graph ##ab^{0.3}=a \cdot (b^{0.3})=100## for control:
http://www.wolframalpha.com/input/?i=a*(b^0.3)=100
It's a hyperbola. The constants ##100## and ##0.3## are only a matter of scaling.
What is the name/category of this kind of web service? An online calculator?

Thank you
 
Last edited:
mech-eng said:
What is the name/category of this kind of web service?

Thank you
I don't know, how it is named and by whom. Wolframalpha is a well-known company that provides solutions for simple equations. More detailed solutions and graphics have to be paid by a membership, but for a quick and dirty look-up, they are a good source. Here's another page with similar properties: https://www.desmos.com/calculator
 
Are there CAD versions and multiphysics versions of such programs?

Thank you.
 
mech-eng said:
Are there CAD versions and multiphysics versions of such programs?

Thank you.
I don't know. Perhaps you could search for them on Google. "free CAD software" of "physics simulations" could be a start.
 
mech-eng said:
I would like to sketch the graph of equation a*b^0.3=constant for a and b are positive real numbers

In experimental work where you might be needing to determine the actual values for the exponent and the constant from your graph it is often useful to use log axes .

Simple example :

The function y = k . xn then it can be rewritten as log y = log k + n . log x

Plotted on log axes the graph curve now becomes a straight line with n and k being given by the slope and intercept .
 
  • #10
Is this a linearization process? This is very confusing for me because shape of the original and converted one is different so what is same?

Thank you.
 

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