Question 408209
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Hi
Using the vertex form of a parabola, {{{y=a(x-h)^2 +k}}} where(h,k) is the vertex
f*x)= -x^2 + 7  |vertex is (0,7) Parabola opens downward (a = -1 < 0)
Line of symmetry is the y-axis. f(x)maximum is 7.
{{{drawing(300,300, -10,10,-10,10,
 grid(1),
circle(0, 7,0.4),
graph( 300, 300, -10,10,-10,10,-x^2+7))}}}