Answer: 9000$
Step-by-step explanation:
Let 's use the formula to find the vertex of the parabola:
ax²+bx+c=0
[tex]\displaystyle x_v=-\frac{b}{2a} \\\\ Where :\\\\ y_v- maximum \ \ income \\\\ y_v=a(x_v)^2+bx_v+c \\\\ Then \ in \ \ our \ \ case : \\\\ -4p^2+1200p =0 \\\\ x_v=-\frac{1200}{-4\cdot 2} =150 \\\\ y_v=-4\cdot (150)^2+150\cdot 1200 \\\\ y_v=150\cdot 1200-150\cdot 600 \\\\ y_v=600\cdot 150=\bf 9000 \[/tex]
