Axis of symmetry is a line passing through the vertex which divides the curge into two parts such tha each part looks the same.
For
, the 'x' part is squared and the coefficient of 
is positive. Hence, the curve will be a parabola facing up which means that the axis of symmetry will be a vertical line. i.e. x = m.
Investigating, f(-1) =
f(-1.5) =
f(-2) =
From these, the curve has a vertex at point (-1.5, -6)
Therefore the axis of symmetry is line x = -1.5 (i.e. the third option)
For
Investigating, f(-1) =
f(-1.5) =
f(-2) =
From these, the curve has a vertex at point (-1.5, -6)
Therefore the axis of symmetry is line x = -1.5 (i.e. the third option)