Creating an Uneven Graph: How to Adjust Slope in Different Quadrants

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Discussion Overview

The discussion revolves around how to create a graph that resembles the absolute value function f(x) = |x|, but with different slopes in different quadrants, particularly focusing on the third quadrant. Participants explore various mathematical approaches and formulations to achieve this effect.

Discussion Character

  • Exploratory
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant inquires about creating a graph similar to f(x) = |x| but with differing slopes in the third quadrant compared to the first quadrant.
  • Another participant suggests a specific function, f(x) = -|x+1| + 10, and requests clarification on the original question.
  • A participant explains that they want the angle of the graph to remain at the origin while not having the y-axis bisect the angle.
  • One participant proposes a piecewise function, f(x) = { ax, x ≥ 0; -bx, x < 0 }, where a and b are positive constants and a ≠ b, to achieve different slopes on either side of the y-axis.
  • Another participant expresses uncertainty about whether a closed formula is needed or if a piecewise function would suffice.
  • A suggestion is made for an alternative formulation: y = ((a+b)/2) |x| + ((a-b)/2) x, which is acknowledged as a suitable solution for the original query.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best approach to create the desired graph. Multiple viewpoints and proposed functions remain, indicating ongoing exploration of the topic.

Contextual Notes

There is uncertainty regarding the specific requirements for the function, such as whether a closed formula is necessary or if piecewise functions are acceptable. The discussion also highlights the need for clarity in the original question posed by the OP.

nhmllr
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This isn't really about whether a graph is odd or even, but I couldn't think of a better title
How does one make a graph like f(x) = |x|, but in the third quadrant the slope is different from the 1st quadrant?
 
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f(x) = -|x+1| + 10?

You might want to be more specific in your question. What you said doesn't really make much sense. When you want a graph like f(x) = |x|, what do you mean?
 
gb7nash said:
f(x) = -|x+1| + 10?

You might want to be more specific in your question. What you said doesn't really make much sense. When you want a graph like f(x) = |x|, what do you mean?

Ok, what I mean is that if you picture the point at which the function bends as an angle, I STILL want the angle to be at the origin, however I don't want the y-axis to bisect the angle
 
Consider that [tex]f(x)=\left\|x\right\| \Leftrightarrow f(x)=\left\{^{x,x \geq 0}_{-x,x < 0}[/tex] and that the angle is bisected iff the slope is the same on both sides. So, make it different on both sides. [tex]f(x)=\left\{^{ax,x \geq 0}_{-bx,x < 0}[/tex] where [tex]a,b>0;a\neq b[/tex]
 
I'm not sure if the OP is looking for a closed formula, or if a piecewise formula is ok. I can't think of a closed formula.
 
There's nothing wrong with using a piecewise function, but if you've got something against it you can always use :

[tex]y = \left(\frac{a+b}{2} \right) |x| + \left(\frac{a-b}{2} \right) x[/tex]
 
uart said:
There's nothing wrong with using a piecewise function, but if you've got something against it you can always use :

[tex]y = \left(\frac{a+b}{2} \right) |x| + \left(\frac{a-b}{2} \right) x[/tex]

Ah! This was EXACTLY what I was looking for- even better! This was for a physics problem, so really I wanted only one function. Thank you!
 

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