I forgot what the formula for this is.

[flyingpig]

If I give you a function f(x) (cartesian) and I ask you to rotate it about the x-axis (counterclockwise) by an angle phi, what is the new function formula?

I remember I did this with matrices, but I can't remember the one for functions. For convenience, let angle phi be 0, pi/2, 3pi/2, and 2pi.

I am guessing 0 would remain the same. I just don't know how to use matrices on functions.

Does anyone understand my question?

 

[BloodyFrozen]

A rotation matrix?

http://en.wikipedia.org/wiki/Rotation_matrix

http://en.wikipedia.org/wiki/Rotation_matrix#Common_rotations

 

[Kevin_Axion]

There's obviously SO(n) but that's matrices.

Doesn't Euler's formula do that same thing?

e^{i\theta} = cos\theta + isin\theta

EDIT: Euler's formula is only for complex numbers.

 

[flyingpig]

Yes, but for functions. Is there no equivalence? I kinda had something like this for conics

 

[flyingpig]

There's obviously SO(n) but that's matrices.

Doesn't Euler's formula do that same thing?

e^{i\theta} = cos\theta + isin\theta

EDIT: Euler's formula is only for complex numbers.

No real numbers please

 

[gsal]

Hhhmmm...if you have a set of points, I can see being rotated with a transformation matrix...but a function? If you have a function f(x) and you "rotate" it 90 degrees...chances are it will stop being a function!...at least, in the sense of the new fnew(x) = trans(forig(x))

 

[I like Serena]

Your function would be a 3-dimensional function, meaning you have fx(x), fy(x), and fz(x).

You can find the appropriate rotation matrix in the article BloodyFrozen gave:
http://en.wikipedia.org/wiki/Rotation_matrix