[填空题]
Let $f(x)=3 x^{2}+12 x+9$ , for $x \in \mathbb{R}$ .
1. For the graph of f , find:
1. the y -intercept; (a,b) a = b =
2. the x -intercepts. (a,b) a = b = (c,d) c = d =
The function f can be written in the form $f(x)=a(x-h)^{2}+k$ .
2. Find the values of a, h and k . a = h = k =
3. For the graph of f , write down:
1. the coordinates of the vertex;(a,b) a = b =
2. the equation of the axis of symmetry.
The graph of a function g is obtained from the graph of f by a reflection
in the x -axis, followed by a translation by the vector $\binom{0}{4}$ .
4. Find g(x) , giving your answer in the form $g(x)=p x^{2}+q x+r$ .
