#How do I solve this?

28 messages · Page 1 of 1 (latest)

stable laurel
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The vetctor space is given by:
r = {1,1,2,3}t1 + {1,4,2,1}t2
So:
x = t1 + t2
y = t1 + 4t2
z = 2t1 + 2t2
w = 3t1 + t2
Letcs take the first and fourth equations.
x = t1 + t2
w = 3t1 + t2
From here we get t1 = (w - x)/2, t2 = (3x - w)/2.
Now, the second and third equations.
y = t1 + 4t2
z = 2t1 + 2t2
From here we get t1 = (2z - y)/3, t2 = (2y - z)/6.
So, combining all that, we get two equations for x, y, z, w:
(w - x)/2 = (2z - y)/3
(3x - w)/2 = (2y - z)/6
Simplifying a bit, we get:
3x - 2y + 4z - 3w = 0
9x - 2y + z - 3w = 0

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Of course, this answer isn't unique, but all answers will be systems of 2 equations in 4 variables.

slow sedge
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This is the solution I had

stable laurel
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No, that's also correct.

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As I said - infinitely many solutions to this.

slow sedge
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Thank you

stable laurel
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Why did you delete it?

slow sedge
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Because I'm scared my school is watching

stable laurel
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Huh...

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Well, alright...

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I just wanted to tell you that you can simplify your equations by gettid rid of rational coefficients.

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So, multiply the first one by -1 and the second by 3.

slow sedge
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The first one by -1?

stable laurel
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Well, yeah. I just prefer when the leading coefficients are positive.

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Oh, and then the second one by -3.

slow sedge
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Ahh oaky

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Wouldn't that be changing the equation though?

stable laurel
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That isn't required, of course. I just find it aesthetically pleasing.

stable laurel
slow sedge
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Ohhh

stable laurel
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You can multiply equations by any nonzero constants, it doesn't change them.

slow sedge
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Man thank you

stable laurel
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You're welcome!

slow sedge
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Do you mind telling mehow you isolated for t1 and t2 in your solution? (t1 = (w - x)/2, t2 = (3x - w)/2)

stable laurel
slow sedge
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Ohh ok

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If you aren't too busy, can you help me with some other stuff please?

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I have a couple of questions I have 0 idea on how to solve :/