Math Is Fun Forum

sara_uk

Guest

matices

i'm stuck on this question and i'm gonna die!
i know that it is really simple but i just can't do it!

Question:

solve the following using guassian elimination:

x-2y+5z=15
2x+y-3z=1
x-7y+18z=17

any help would be really appreciated
cheers in advance

(1 day till christmas )

sara_uk

Guest

Re: matices

i just noticed that i spelt matrices wrong

also it is not possible to solve, because the equation is inconsistent therefore there are no solutions!

please tell me if i'm wrong

also if you really want to help i've got another question that i'm stuck on (come to think of it i've got a few that i'm stuck on but they can wait till after christmas)

Question:

By considering the images of the unit vectors (1 0)T and (0 1)T  in R2 under the following transformations, find the matrix representing the transformation.
(i) Reflection in the line y = ax
(ii) Reflection in the line y = mx
(iii) Rotation (anticlockwise) through 60º
(iv) Rotation (anticlockwise) through general angle a

(imagine that a is the greek letter theta, and that T is a power meaning transpose)

i think i know how to do them all except (ii)

any tips?

again cheers in advance!

sara_uk

Guest

Re: matices

i seem to be making so many mistakes

for the second question part (i)

the a represents a minus:

(i) y=-x

krassi_holmz

Real Member

Registered: 2005-12-02

Posts: 1,905

Re: matices

The system has not solution indeed.

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