- #1
laminatedevildoll
- 211
- 0
Find the matrix of a relflection at y=-4x.
I found out that b1 = [1,-4] in the direction y = -4x
I found out that b2 = [-4,-1] orthogonal to the line
Therefore,
rho(b1) = b1 - 4b2
= -4b1 - b2
Will the matrix be
|1 -4 |
|-4 -1|
Find the matrix of rotation, if the angle of rotation is 45 degrees, the axis of rotation points in the direction of [1,2,2] and if the rotation id counterclockwise. Also repeat the same problem, if the rotation is clockwise.
I started off saying that
I found an orthogonal vector to [1,2,2]
b1=[ -4,1,1]
b3= [1/(sqrt5), 1/(sqrt5), 1/(sqrt5)]
b2 = -b1 * b3
Am I on the right track?
I found out that b1 = [1,-4] in the direction y = -4x
I found out that b2 = [-4,-1] orthogonal to the line
Therefore,
rho(b1) = b1 - 4b2
= -4b1 - b2
Will the matrix be
|1 -4 |
|-4 -1|
Find the matrix of rotation, if the angle of rotation is 45 degrees, the axis of rotation points in the direction of [1,2,2] and if the rotation id counterclockwise. Also repeat the same problem, if the rotation is clockwise.
I started off saying that
I found an orthogonal vector to [1,2,2]
b1=[ -4,1,1]
b3= [1/(sqrt5), 1/(sqrt5), 1/(sqrt5)]
b2 = -b1 * b3
Am I on the right track?