Y1= -x^2
y2= -4
y1=y2
-x^2= -4
x^2=4
x1=2, x2= -2
2х^2=10
x^2=5
x=±<span>√5
...</span>
Y=x²+4x+3
a=1, b=4, c=3
x(в) = -b/2a = -4/(2*1) =-4/2=-2
y(в)=(-2)²+4(-2)+3=4-8+3=-1
(-2;-1) - координаты вершины параболы
8.4-(1+tg^2a)=8.4-(1/cos² α)=8.4-(1/(cos α * cos a))=8.4-(1/(1/9))=8.4-9=-0.6