How Do You Solve Systems of Linear Equations with Parameters?

Click For Summary
The discussion focuses on solving systems of linear equations with parameters, providing general solutions for different variable assignments. The first part presents equations where x, y, and z are expressed in terms of parameters a, b, r, and t. A participant questions whether using arbitrary equations like x + 2y = 1 and 2y - z = 2 would suffice, but another clarifies that these do not represent the required conditions for a plane intersection. The consensus is that the equations must be aligned to form a single plane rather than intersecting lines. The conversation emphasizes the need for consistency in the equations to achieve the desired solution.
songoku
Messages
2,508
Reaction score
402
Homework Statement
1. Find a linear equation in the variables x, y and z that has a general solution:
x = 3 - 4p + q
y = p
z = q
where p and q are arbitrary parameters

2. Express a general solution for the equation in part (1) in two other different ways

3. Write down a linear system of two different non zero linear equations such that the system has the same general solution as in part (1)
Relevant Equations
Not sure
1)
x = 3 - 4p + q
x = 3 - 4y + z
x + 4y - z = 3

2) x + 4y - z = 3
(i) let x = a and y = b, so z = a + 4b - 3
General solution:
x = a
y = b
z = a+ 4b - 3

(ii) let x = r and z = t, so y = (3 - r + t) / 4
General solution:
x = r
y = (3 - r + t) / 4
z = t3) I don't understand this part. Is the answer the same as part (1)? Can I just take random equations like x +2y = 1 and 2y - z = 2? Is this the form asked by the questions?

Thanks
 
Physics news on Phys.org
Strange question. I don't think your two equations in (3) will do it. You have two planes that aren't parallel and their intersection would be a line, not a plane. He is asking for two linear equations (planes) whose intersection would be a plane. Seems to me they have to be the same plane. Maybe ##2x+8y-2z = 6,~5x+20y - 5z = 15##? Seems pretty silly to me.
 
  • Like
Likes songoku
LCKurtz said:
Strange question. I don't think your two equations in (3) will do it. You have two planes that aren't parallel and their intersection would be a line, not a plane. He is asking for two linear equations (planes) whose intersection would be a plane. Seems to me they have to be the same plane. Maybe ##2x+8y-2z = 6,~5x+20y - 5z = 15##? Seems pretty silly to me.

Not sure, maybe that is the answer. Thank you very much
 

Similar threads

Replies
1
Views
2K
Replies
2
Views
2K
Replies
18
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
8
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 22 ·
Replies
22
Views
4K
Replies
10
Views
3K