The line x = 1 is vertical line in coordinate plane, parallel to y-axis.


This line passes through the point x=1 at x-axis and has x-coordinates of all its points equal to 1.


The point P=(3,4) lies 2 units to the right from the line x=1.

Therefore, its image after reflection lies 2 units to the left from the line x=1.


Thus x-coordinate of the image is  1-2 = -1.


y-coordinate of the image is the same as for the original point y=4.


Thus the answer is: the image of the point P=(3,4) after reflection about the line x=1 is the point Q=(-1,4).