Quadratic Function: Axis of Symmetry

The axis of symmetry is the line
that cuts the graph
into two symmetric pieces.

For a quadratic function
y = ax² + bx + c,

the axis of symmetry (green dashed line) is
x = -b/2a.

The given quadratic function is
y = 1x² + 4x + 5.

a = 1
b = 4

So the axis of symmetry is
x = -4/[2⋅1].

-4/[2⋅1] = -4/2

-4/2 = -2

So [x = -2] is the answer.

The given quadratic function is
y = -5x² + x.

a = -5
b = 1

So the axis of symmetry is
x = -1/[2⋅(-5)].

-1/[2⋅(-5)] = -1/[-10]

-1/[-10] = 1/10

So [x = 1/10] is the answer.