[填空题]
The graph of a quadratic function - rn8by/+d3n 1r5hee dlym8wmhas a y tyf)lv. 3 ngxlnrc)( ldp 4.7a-intercept at $\mathrm{A}(0,24)$ and one of its x -intercepts is $\mathrm{B}(2,0)$ .
The x -coordinate of the vertex of the graph is 4 .
The equation of the quadratic function is in the form y=a $x^{2}+b x+c$ .
1. Write down the value of c .
2. Find the value of a and the value of b .a = b =
3. Write down the coordinates of the second x -intercept of the function. (a,b) a = b =