-1 = а*0+b*0+c
c=-1
<span>y=ах^2+bх-1
</span>
-b/2a = -1
<span>-4=а(-1)^2+b(-1)-1
</span>
b=2a
<span>-4=а-b-1
</span>
b=2a
<span>-4=а-2a-1, -4=-a-1, a=3
</span>
b=2a=2*3=6
a=3, b=6, c=-1
11x²+121x=0
11x(x+11)=0
11x=0 x+11=0
x=0 x=-11
√(9-4√5)=√5-2
===========================================
f`(x)=-2x/2V(4-x^2)=-x/V(4-x^2)