Answer:
midpoint is the answer.....
She probably does that for exercise. So, she gets to the level that she wants, and she gets more exercise so she gets there faster.
These functions are expressed in the factored form: what this means is that say for the first one y=(x-4)(x-1)(2+x)(3+x) ... when x=4, the first bracket becomes 0. Same for x=1, x=-2, x=-3 ...
If you were to graph this, you would see that the function's line interesects the x-axis at these points... when x=4, when x=1, etc etc.
Thus, take a look at the zeroes of the graph. At which x points do they interscet the x-axis? You can determine the equation of your graph by this.
Diameter x pi (3.14) OR 2 x radius x pi
F(x) = (x+6) (x+6) since this will sure into x + 6 ^2
