Question

Помогите, прошу! Найдите координаты точек пересечения графиков функций:
$y=-0,5x ^{2} +2,5 y = 2x^{2} +5x$

Answer 1

$-0.5x^2+2.5=2x^2+5x\ 2.5x^2+5x-2.5=0\ 25x^2+50x-25=0\ D=2500+4*25^2=(50sqrt{2})^2\ x=frac{-50+50sqrt{2}}{50}=sqrt{2}-1\ x=frac{-50-50sqrt{2}}{50}=-1-sqrt{2}$ 
$y=-0.5(sqrt{2}-1)^2+2.5=0.5sqrt{2}+1\ y=-0.5(-sqrt{2}-1)^2+2.5=4+0.5sqrt{2}$