Answer
$(-1,9)$.
Work Step by Step
If the equation of a quadratic function is $f(x)=\pm(x-k)^2+m$. Then the vertex of the function is at $(k,m)$.
$-x^2-2x+8=-1(x^2+2x)+8=-(x+1)^2+1+8=-(x+1)^2+9$
Hence here the vertex is $(-1,9)$.
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