Hello!
To calculate the axis of symmetry coordinates, you should use the following equation:
xa = -b/2a
ya = f(xa)
Then, let’s start with xa:
xa = -(-8)/2*1 = 8/2 = 4
ya = f(xa) = f(4) = (4)^2 - 8(4) + 15
f(4) = 16 - 32 + 15 = -1
So, the axis of symmetry coordinates are (4, -1).
