Parametic y= sqrt(t +1) and y = sqrt(t-1)

  • Thread starter Jbreezy
  • Start date
In summary, the student is trying to find an equation in Cartesian form for a curve that has two points, t = -1 and t = 1. If they just solve for t, they get 0 = 2 and the curve is undefined. They realize there is a typo in the problem and need help from the community to find the correct equation.
  • #1
Jbreezy
582
0

Homework Statement



I have to eliminate the parameter and write in Cartesian form.

Homework Equations




y= sqrt(t +1) and y = sqrt(t-1)

The Attempt at a Solution



If you were to just go for the gusto and square it out you will end up with 0 = 2. Clearly I'm missing something here. Just stumped. I don't think the right way to go is squaring and setting them equal.
 
Physics news on Phys.org
  • #2
Can you post the *exact* problem statement please?
 
  • #3
Yep,

Eliminate the parameter to find a Cartesian equation of the curve.

y = sqrt(t +1) , y = sqrt(t -1)
 
  • #4
I think perhaps one of the y's is supposed to be an x.
 
  • #5
Ha It is possible. There was a misprint on one of the graphs where it was supposed to say seconds and it was like hours. So I suppose. I just didn't know if I was missing something. Seems like you would just do as I said and square it and yatta but you get 0 = 2.
 
  • #6
Unless I am missing something obvious, I don't think it has a solution as given.
 
  • #7
Not sure maybe someone else has ideas too?
 
  • #8
Jbreezy said:
Not sure maybe someone else has ideas too?

Yeah, cepheid is right. There is clearly a typo in the problem. It's just expressing y in terms of two contradictory equations in t. There should be an x in there somewhere.
 
  • #9
Jbreezy said:

Homework Statement



I have to eliminate the parameter and write in Cartesian form.

Homework Equations

y= sqrt(t +1) and y = sqrt(t-1)

The Attempt at a Solution



If you were to just go for the gusto and square it out you will end up with 0 = 2. Clearly I'm missing something here. Just stumped. I don't think the right way to go is squaring and setting them equal.

These are NOT "parametric equations" and CANNOT be put in "Cartesian" form without an "x". As others have suggested, it must be [itex]x= \sqrt{t+ 1}[/itex] and [itex]y= \sqrt{t- 1}[/itex]. Yes, square both, then solve for t and set the two equations for t equal.
 
  • #10
OK then there is a typo in my book. Thanks for the help I will bring it up in lecture.
 

1. What is the difference between parametric equations and standard equations?

Parametric equations represent mathematical relationships between two or more variables, while standard equations represent a relationship between variables in terms of a single variable. In parametric equations, each variable is defined in terms of a third variable, called a parameter, while standard equations do not have this parameter.

2. What is the significance of the square root in these parametric equations?

The square root in these equations represents the inverse function of squaring a number. In other words, it is the function that undoes the squaring operation. In these particular equations, the square root is used to represent the positive square root of a number, as the negative square root is not typically used in parametric equations.

3. How do these parametric equations relate to a graph?

When these equations are graphed, they create a curve known as a parabola. The parameter t represents the x-coordinate of points on the parabola, while the y-coordinate is represented by the function value of either of the equations. As t increases, the points on the parabola move to the right, and as t decreases, the points move to the left.

4. What is the domain and range of these parametric equations?

The domain of these equations is all real numbers greater than or equal to 1, as the square root function is undefined for negative numbers. The range is all real numbers greater than or equal to 0, as the square root function always produces positive values.

5. How are these parametric equations used in real-life applications?

Parametric equations are used in many fields of science and engineering, including physics, biology, and computer graphics. In particular, these equations can be used to model the motion of objects in projectile motion and to create smooth, curved lines in computer graphics. They are also used in statistical analysis and data modeling.

Similar threads

  • Calculus and Beyond Homework Help
Replies
2
Views
185
  • Calculus and Beyond Homework Help
Replies
12
Views
988
  • Calculus and Beyond Homework Help
Replies
1
Views
7K
  • Calculus and Beyond Homework Help
Replies
2
Views
3K
  • Calculus and Beyond Homework Help
Replies
3
Views
119
  • Calculus and Beyond Homework Help
Replies
12
Views
1K
  • Calculus and Beyond Homework Help
Replies
28
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
493
  • Precalculus Mathematics Homework Help
Replies
10
Views
295
  • Calculus and Beyond Homework Help
Replies
16
Views
1K
Back
Top