Answer:
The parent function is
That Parabola's equation is
Step-by-step explanation:
I can't really explain much, but the top equation is a formula for <em>all </em>equations for a parabola. h and k are the x and y-values of the vertex. a is, well, a.
How did I find the equation of the parabola? Simple. Since the vertex is on the origin, h and k are 0. Also, because it intercepts (2,4) and (1,1), a=1.
A reflection over the line y=x implies exchanging the x and y coordinates of a point. For example if you take a generic point (a,b) then its reflection over y=x is (b,a). Our point is (-1,3) so its reflection over y=x is the point (3,-1).
Then we have to translate it two units left. Translating a point left means that we are moving towards negative x values so we need to substract 2 from the x coordinate:
Finally we have to translate it 1 unit up towards positive y values so we have to add 1 to its y coordinate:
And these are the final coordinates. In the following picture you have the points you get after each step (from A to D) with the y=x line in blue:
