MathGroup Archive 2000

[Date Index] [Thread Index] [Author Index]

Search the Archive

parametric equations

  • To: mathgroup at
  • Subject: [mg22021] parametric equations
  • From: MAvalosJr at
  • Date: Thu, 10 Feb 2000 02:26:09 -0500 (EST)
  • Sender: owner-wri-mathgroup at

Hi Everyone:

I have two parameters,x==3 t, and y ==9t^2. I plot them and get my 
Then I get my rectangular equation, i.e, y==x^2.
Now I parametrize the rectangular equation ,y==x^2 and I get completely 
different parametric equations. Both plot the same graph. However,when I plug 
in values for t, in the first case,that is,t=Table[{t,{3 t, 9 t^2},{t,4/3}] I 
get x=4 and y =16.
On the other hand when I do the same operation with the parametrized equation,
t=Table[{t,{-1 + t, (-1 + t)^2, {t,4/3}] I get x=0, y=0. I used this very 
simple example because that how I discovered that my parametrization of 
complicated equations was not giving me the same results as the original 
parameters- even thought the graphs coincided. What am I doing wrong?


  • Prev by Date: Specifying inequalities
  • Next by Date: formula for Pi
  • Previous by thread: Specifying inequalities
  • Next by thread: Re: parametric equations