In the R3 space, we perform two consecutive rotations: in the first one we make a rotation of an angle (θ) leaving the x axis invariant, and in the second one we make a rotation of an angle (π) leaving the z axis invariant. By leaving an axis invariant I mean not moving it, I didn't know how else to put it.
I am asked to find the total rotation angle and the rotation axis.
What I did is to multiply both rotation matrix, therefore obtaining the total rotation matrix. In this matrix I applied the 1 + 2cos(θ) formula and I found that the total angle was π. However I am not sure about this, so I would like to know if I am correct and also how to find the rotation axis.
Thanks in advance.