Is this the correct graph for x=-1+5t when t = −2, −1, 0, 1 and 2?

  • Thread starter Thread starter f22archrer
  • Start date Start date
  • Tags Tags
    Graph
Click For Summary
SUMMARY

The discussion centers on the correct formulation of parametric and vector equations for the line defined by the equation x = -1 + 5t. Participants clarify the parametric equations as x = 3t - 2, y = 2t + 1, and z = -3t - 5, while addressing the need for proper notation in symmetric equations. The confusion arises from the use of different parameters (t vs. s) and the correct interpretation of the original problem statement. Ultimately, the participants emphasize the importance of consistency in parameter usage for accurate graph plotting.

PREREQUISITES
  • Understanding of parametric equations in three-dimensional space
  • Familiarity with vector equations and their representation
  • Knowledge of graph plotting techniques for parametric equations
  • Ability to manipulate algebraic expressions and solve for variables
NEXT STEPS
  • Learn how to derive parametric equations from vector equations
  • Study the use of different parameters in parametric equations
  • Explore graphing tools for visualizing parametric equations
  • Investigate the implications of using different parameters on the resulting graph
USEFUL FOR

Students in mathematics, particularly those studying calculus or linear algebra, educators teaching parametric equations, and anyone involved in graphing and visualizing mathematical concepts.

f22archrer
Messages
14
Reaction score
0

Homework Statement



Write the parametric and vector equations of:

x + 2 / 3 = y − 1 / 2 = z + 5/ -3

x=-1+5t
and plot a graph of this line when t = −2, −1, 0, 1 and 2.

Homework Equations



vector:
r= [-2,1,-5]+t[3,2,-3]
parametric
x=3t-2
y=2t+1
z=-3t-5

using parametric equation:: i drew the graph, please check if the graph is correct at -2,-1,0,1,,2

The Attempt at a Solution

 

Attachments

  • intersecting lines 002.jpg
    intersecting lines 002.jpg
    30.3 KB · Views: 505
Physics news on Phys.org
f22archrer said:

Homework Statement



Write the parametric and vector equations of:

x + 2 / 3 = y − 1 / 2 = z + 5/ -3

x=-1+5t
and plot a graph of this line when t = −2, −1, 0, 1 and 2.

Homework Equations



vector:
r= [-2,1,-5]+t[3,2,-3]
parametric
x=3t-2
y=2t+1
z=-3t-5

using parametric equation:: i drew the graph, please check if the graph is correct at -2,-1,0,1,,2

The Attempt at a Solution


Not sure where that x = -1+5t came from. But your parametric equations look correct. I didn't check all your points, but if you plotted the points to scale as apparently you did, and they came out on a straight line, aren't you pretty confident in the answers?
 
actually i was worried about the axis ... in specific the z axis.. i just had this gut feeling like i took -z the wrong direction ...
 
x=-1+5t is part of the question .
 
f22archrer said:
Write the parametric and vector equations of:

x + 2 / 3 = y − 1 / 2 = z + 5/ -3

Based on your subsequent work, your symmetric equations need parentheses.

Here are the equations, using LaTeX.

$$ \frac{x + 2}{3} = \frac{y - 1}{2} = \frac{z + 5}{-3}$$

When you write them in plain text, they should look like this:

(x + 2)/3 = (y - 1)/2 = (z + 5)/(-3)

What you wrote means the following:
x + ##\frac{2}{3}## = y - ##\frac{1}{2}## = z + ##\frac{5}{-3}##
 
f22archrer said:
x=-1+5t is part of the question .

Then doesn't it seem odd that you are saying x=3t-2 in the solution? I assume when you are writing "x + 2 / 3" you mean (x+2)/3, not x+(2/3). But even assuming that, your parametric form looks screwed up. Put x=(-1)+5t into (x+2)/3=(y-1)/2 and solve for y in terms of t. The 't' in your equations is the wrong parameter. Your are going to get the same line, but the points corresponding to a given value of t will be different.
 
Last edited:
hey , sorry for late response but if i put x=-1+5t in [x+2]/3= [y-1]/2=[z+5]/-3 what will i get after... how do i solve for y
 
f22archrer said:
hey , sorry for late response but if i put x=-1+5t in [x+2]/3= [y-1]/2=[z+5]/-3 what will i get after... how do i solve for y
Are you asking how to solve
\displaystyle \frac{(-1+5t)+2}{3}=\frac{y-1}{2}​
for y ?

Give it a try.

What do you get?
 
i didnt mean how i will solve it..rather i was concerned about what too do after i get the Y value


y =[5+10t]/3
 
  • #10
f22archrer said:
i didnt mean how i will solve it..rather i was concerned about what too do after i get the y value

y =[5+10t]/3
That depends.

What is it you're trying to do next?
 
  • #11
f22archrer said:
x=-1+5t is part of the question .
Then you have two different expessions for x a function of t. What are you supposed to use?
 
  • #12
next i need to find vector and parametric equation and then plot for t ...|
 
  • #13
This seems like a very strange way to phrase the problem, making me wonder what the exact statement of the problem is.

f22archrer said:

Homework Statement



Write the parametric and vector equations of:

x + 2 / 3 = y − 1 / 2 = z + 5/ -3

x=-1+5t
and plot a graph of this line when t = −2, −1, 0, 1 and 2.

Homework Equations



vector:
r= [-2,1,-5]+t[3,2,-3]
parametric
x=3t-2
y=2t+1
z=-3t-5

Taking the problem as you have quoted, don't use ##t## here. You apparently should write:
x=3s-2
y=2s+1
z=-3s-5
using s for your parameter. Now if x = -1+5t you can put that in and get s in terms of t. Then use that in these last three equations. Of course, this all assumes I understand what you are trying to do.
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
Replies
4
Views
3K
Replies
10
Views
2K
Replies
8
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 12 ·
Replies
12
Views
3K
Replies
12
Views
8K
Replies
8
Views
3K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 23 ·
Replies
23
Views
2K