Quick Question: Is this matrix an orthogonal projection?

AI Thread Summary
The matrix P is analyzed for orthogonality in terms of its null space and range. It is determined that the range is spanned by the vector [0, 1], while the null space is spanned by the vector [1, -1]. Since these two vectors are not perpendicular, the matrix does not represent an orthogonal projection. Therefore, the conclusion is that the matrix P is not an orthogonal projection. The discussion effectively clarifies the conditions for orthogonal projections in relation to the given matrix.
mistymoon_38
Messages
18
Reaction score
0
[SOLVED] Quick Question: Is this matrix an orthogonal projection?

Homework Statement


P=[0 0 ]
[11]


Homework Equations





The Attempt at a Solution



Its orthogonal if the null space and range are perpendicular.
Range=[0 ]
[x+y]
null space=[x
 
Physics news on Phys.org
null space=[x ]
[-x]??
So then its not orthogonal??
 
If you mean the range is spanned by the vector [0,1] and the null space is spanned by the vector [1,-1] (which I think you do mean) then yes, not orthogonal.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top