[填空题]
The graph of a quadratic function ha 1pr(wi rux(kvx qtm::4uz3y7s a y-intercept at A9u zdr: sd:/ouv-:xz s 8gxdy:(0,24) and one of its x-interced s:u:y9dosdzxr8:vx:z/g - upts is 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$x^2$+bx+c.
1.Write down the value of c. c =
2.Find the value of a and the value of b. b =
3.Write down the coordinates of the second x-intercept of the function.
(a,b) a = b =