Given that B is a point equidistant from points A and C. We are to determine AB=AC.
In order to determine AB=AC, we need the coordinates of A, B, and C, or we need the coordinates of A and C and an indication of the distance from the midpoint of AC to B.
Statement 1: The coordinates of the points A and C are (1,2) and (2,1), respectively
Statement 1 gives us the coordinates A and C without coordinate of B. We have no idea of the relationship between the midpoint of AC and point B, hence we are unable to determine the exact distance between AB=AC, which can be √((2-1)^2+(1-2)^2)/2 = (√2)/2, if C B is located at the midpoint of A and C or any number depending on the coordinate of B. Statement 1 is insufficient.
Statement 2: The distance between A and C is √2
Statement 2 is clearly insufficient. Knowing the distance between A and C, we only need to know the distance or relationship between the midpoint of A and C and point B. Since we are not privy to this information, statement 2 is insufficient.
1+2
still insufficient. The information provided in statement 2 can be gotten from statement 1. Hence, combining statements 1 and 2 does not provide any new useful information.
The answer is E.