I: X and Y should be in one-to-one correspondence. After rotation, 1 X is not allowed to correspond to 2 Y value.
Or,
II: The tangent L passing through the intersection point A of Y = (4+6x-x 2-2) 0.5 with the Y axis cannot intersect with the straight line parallel to the Y axis after rotation.
In this way, it can be judged that when L rotates perpendicular to the X axis, it is the limit position of α.
This angle is equal to the angle θ between the tangent of the circle at point A and the Y axis.
Answer (0, √2)
C(3,0)
tanθ=√2/3,0 & lt; =α& lt; =θ
Namely 0
The fourth floor made a detour when calculating the angle.
See the picture.