Chapter 9.1 is about find the midpoint with two other points. You have to get the plots for the other two points to plug into the formula.
Formula - m(x1+x2/2 , y1+y2/2 )
Then you use the distance formula to find the distance between the two points .
Distance formula- D= | (x2-x1)^2 + (y^2-y^1) m^2
.......9.2 ^ the standard formula is introduced finding the axis of symetry
Standard formula- y=a(x-h)^2+k
9.3 is about the standard form of a circle
Standard form of a circle - (x-h)^2 + (y-k)^2 = r^2
This for ula finds the center of the circle and the point in the circle .