Linear Transformation Matrix for Rotations about y-axis

  • Thread starter Thread starter robierob12
  • Start date Start date
  • Tags Tags
    Linear Rotations
robierob12
Messages
48
Reaction score
0
Derive the matrix for the transformation that rotates a point (x,y,z) counterclockwise about the y-axis through an angle (X).

My book gives me a matrice for the y-axis move.

(cosX 0 sinX)
(0 1 0 )
(-sinX 0 cosX)

call the above matrix [A]


Im also given this formula for a unit vector

cos(V)i + cos(W)j + cos(Y)k


The way that I see the question, is that I need to somehow derive matix [A]
from the given unit vector formula.

I just don't see exactly how they are connected here.

I really DON'T want the solution for this, just some insight maby on the connection between the formula and the matrix.


I know that if I have a vector u and an angle (X) I can just multiply
Au to get the rotated vector. So I do know how to use the matrix.
 
Physics news on Phys.org
The formula can be written as a matrix vector (cos(V) cos(W) cos(Y))^T.

You are really looking for the linear transformation matrix such that L(x,y,z) rotates the standard basis for lR^3 by an angle X.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top