15, if the x axis and the y axis are reversed, you will know that it is y = x 2 -2, and the vertex (0,-2).

Now change them back, that is x = y 2-2.

So choose one

Y is related to the square root of X.

x 4 9 36

Root number x 2 3 6

y 1 1.5 3

From the above, it can be seen that the relationship between the root numbers X and Y is 2: 1, so for 3, the corresponding value is 1.5.

8, f(x+5)=f(x), indicating that the period of the image is 5.

As can be seen from the figure, there are four solutions between f(x)=0, so there are exactly 1 solutions.

So there are 4+4+ 1=9 solutions, choose B.

10, from the diagram, k=f(3)=4, g(k)=g(4)=5.

So choose e