Converting Tricky Parametric Equations into a Single Function | Tips & Tricks

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Discussion Overview

The discussion revolves around the challenge of converting specific parametric equations into a single function of the form f(x,y) = 0. The focus is on the equations X(t) = t^2 + t + 1 and Y(t) = t^2 - t + 1, particularly addressing the complications arising from imaginary roots and the process of isolating variables.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant expresses difficulty in isolating either X or Y due to the imaginary roots of the parametric polynomials.
  • Another participant notes that the relationship x - t = y + t can be derived by subtracting Y(t) from X(t).
  • A different participant reiterates the challenge of converting the parametric equations and suggests that X - Y = 2t can be used to find t in terms of X or Y before substitution.
  • Some participants propose substituting t = (x - y) / 2 as a straightforward method to avoid solving the quadratics.
  • One participant acknowledges their oversight in not recognizing the substitution earlier, despite noting the relationship x - y = 2t.

Areas of Agreement / Disagreement

Participants present multiple approaches to the problem, with some advocating for substitution methods while others emphasize the need to solve the quadratics. No consensus is reached on the best method to proceed.

Contextual Notes

The discussion highlights the potential complications arising from imaginary roots and the assumptions involved in isolating variables from the parametric equations.

Gagle The Terrible
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I would like to convert these parametric equations into a single
f(x,y) = 0 function.

X(t) = t^2 + t + 1
Y(t) = t^2 - t +1

In fact, what stops me is the imaginary roots of the parametric polynomials.

Is there a way to get around the seemingly impossible explicit solving of the quadratics to isolate either X or Y ?
 
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Note that x - t = y + t (or just subtract y(t) from x(t)).
 
Last edited:
Gagle The Terrible said:
I would like to convert these parametric equations into a single
f(x,y) = 0 function.

X(t) = t^2 + t + 1
Y(t) = t^2 - t +1

In fact, what stops me is the imaginary roots of the parametric polynomials.

Is there a way to get around the seemingly impossible explicit solving of the quadratics to isolate either X or Y ?

First note that X - Y = 2t, but also notice that these are both quadratic equations so you can solve one of them or the other to find t in terms of X or Y and then substitute this into X - Y = 2t or the equation for the other variable.
 
You just want to substitute t = (x - y) / 2. There's no need to solve any quadratics.
 
0rthodontist said:
You just want to substitute t = (x - y) / 2. There's no need to solve any quadratics.

Darn, I guess I should have seen that since I did notice that x - y = 2t.
 

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