Answer:
Vertex: (5,-4)
Axis of symmetry: x=5
X-intercepts: (3,0) and (7,0)
Y-intercept: (0,21)
Explanation:
The vertex would be the tip of the parabola, so the vertex is (5,-4)
The axis of symmetry would be a line cutting a parabola in half indicated by the line x=5
X-intercepts are where a function passes through the x-axis or when y=0, so in this case, the x-intercepts are (3,0) and (7,0)
The y-intercept of a function is where a function passes through the y-axis or when x=0, so our y-intercept is f(0)=0²-10(0)+21=21, or (0,21)