(4+5i)(4-5i)=(4)²-(5i)²=16-25(i)²=16-25(-1)=16+25=41
The parabola vertex is B. (2,2)
Explanation in photo provided.
Y - y1 = m (x - x1)
y1 being the y coordinate
x1 being the x coordinate
m being the gradient (or slope)
y - 5 = 1/3 (x - 0)
y - 5 = 1/3x
y = 1/3x + 5