2007-II-05

Ans: D
According to the function $y=(x+1)^2-4$, we have

1. The coordinates of the vertex of the graph are $(-1,-4)$.
2. The equation of the axis of symmetry of the graph is $x=-1$.
3. Sub. $y=0$ into the function, we have

   $\begin{array}{rcl}
   (x+1)^2 -4 & = & 0 \\
   x^2 +2x +1 – 4 & = & 0 \\
   x^2 +2x -3 & = & 0 \\
   (x+3)(x-1) & = & 0
   \end{array}$

   Therefore, the $x$-intercepts of the graph are $-3$ and $1$.

4. Rewrite the function into the general form, we have

   $\begin{array}{rcl}
   y & = & (x+1)^2 – 4\\
   & = & x^2+2x+1 – 4 \\
   & = & x^2 +2x -3
   \end{array}$

   Therefore, the $y$-intercept of the graph is $-3$.

Hence, D is true.