D=(-4)²-4*3*(-4)=16+48=64=8²
x₁=(4-8):6=-2/3
x₂=(4+8):6=2
D^2=3^2 +4^2 +5^2
d=√(9+16+25))=√(2*25)=5√2
у(х) = sin3x * cos5x - cos3x * sin5x
у(х) = sin(3x-5x)
y(x)=-sin2x
y '(x)=-2cos2x
y ''(x)=4sin2x
y''(п/3)=4sin(2п/3)=
( x + 3 )^2 = 2х + 6
х^2 + 6х + 9 = 2х + 6?
х^2 + 4х + 3 = 0
D = 16 - 12 = 4 ; V D = 2
X1 = ( - 4 + 2 ) : 2 = - 1
X2 = ( - 4 - 2 ) : 2 = - 3
Ответ при х = - 1 ; - 3