Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
Pages: 1
#1 2009-01-21 05:00:09
- FurtherPure1Student
- Guest
Matrix Question - FP1
Hey guys,
I have no idea what this question is actually asking me to do? Where do I start?
The matrix
transforms the point (x,y) to the point (x',y'), where = .Find the values of m such that all points on the line y=mx transform to points which are also on the line y=mx.
Thank you in advance.
#2 2009-01-21 05:23:46
- luca-deltodesco
- Member
- Registered: 2006-05-05
- Posts: 1,470
Re: Matrix Question - FP1
x' = 5x + 10y
y' = -3x - 8y
y = mx, so substitute
x' = 5x + 10mx
y' = -3x - 8mx
you want the transformed point (x', y') to lie on the line y = mx, so
-3x - 8mx = m(5x + 10mx)
-3 - 8m = 5m + 10m²
10m² + 13m + 3 = 0
m = (-13 ± 7)/20
check my working out.
The Beginning Of All Things To End.
The End Of All Things To Come.
Offline
#3 2009-01-21 05:31:38
- FurtherPure1Student
- Guest
Re: Matrix Question - FP1
Ah, thank you for that... but I am still confused about what this is actually meaning. The wording of the question is quite confusing.
#4 2009-01-21 06:50:42
- luca-deltodesco
- Member
- Registered: 2006-05-05
- Posts: 1,470
Re: Matrix Question - FP1
basicly, you have the line y = mx, and you have to find the values of 'm' such that every single point on the line y = mx, would be mapped to a point that is also on the line itself.
The Beginning Of All Things To End.
The End Of All Things To Come.
Offline
Pages: 1