Answer:
x = - 1 is the axis of symmetry
Explanation:
the equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k ) are the coordinates of the vertex and a is a multiplier
y = - 2(x + 1)² + 6 ← is in vertex form
with (h, k ) = - 1, 6 ) ← coordinates of vertex
the line of symmetry of a parabola is a vertical line, passing through the vertex with equation
x = c ( c is the value of the x- coordinate of the vertex , that is - 1 , then
x = - 1 ← equation of axis of symmetry