If the straight line Y=KX+B and the known straight line Y=2X+ 1 are symmetric about y, find the values of k and b. 。

According to the meaning of the question, the intersection of two straight lines is on the Y axis, that is, the two straight lines have a common point (0, b). Substituting this common point into Y=2X+ 1, we get b =1;

It is also obtained from the symmetry of two straight lines about the Y axis, and the slopes of the two straight lines are opposite, that is, K=-2.

In fact, there are times when it is not true, such as X=2 and X=-2. They are symmetrical about y, but there seems to be no slope. Even if there is a slope, it is not reciprocal.