Consider the following quadratic polynomials:
P1(x)=x2−4x+3,
P2(x)=−x2+4x−3,
P3(x)=−x2−4x+3.
The graph drawn in a worksheet is a downward-opening parabola that meets the x-axis exactly at x=1 and x=3. Identify which of the above polynomials represents this graph.