Since the reflection angle is equal to the incident angle, the problem is equivalent to finding a point C on the X axis, so that the acute angles formed by straight lines AC and BC are equal to the X axis.

At this time, there are two ways to do it. The first method is to use the relationship of slope, let C(c, 0), and according to kAC=-kBC, represent kAC and kBC with algebraic expression containing C, and get an equation to solve C. 。

The second method is the answer. Let the symmetry point of B about the X-axis be D, the intersection of AD and X-axis be C, and the left and right sides of C are E and F at will on the X-axis, then according to the symmetry relation, we can get ∠BCE=∠DCE=∠ACF. And ∠BCE is the acute angle formed by BC and X axis, ∞.