Question

Fin the vertex and axis of symmetry of each quadratic.
f(x)=-(x+3)(x+5)

Answer 1

the roots of your quadratic are at x = -3 and x = -5

the axis of symmetry is midway between the roots to find it is

x = (-3 + -5)/2

x = - 4 is the line of symmetry


In general for a quadratic \[ ax^2 + bx + c = 0\]

then the axis of symmetry is

\[x = \frac{-b}{2a}\]

the vertex lies on the axis of symmetry.

to find it you'll need to find f(-4)

then the vertex will be at the ordered pair (-4, f(-4))