a)
[tex]w(x)=0\\x_1=-3\\x_2=-1\\x_3=3\\[/tex]
b)
[tex]w(x)=a(x+3)(x+1)(x-3)=a(x+1)(x^2-9)=a(x^3-9x+x^2-9)=\\\\a(x^3+x^2-9x-9)[/tex]
Obliczam a
[tex]w(0)=a(0^3-0^2-9\cdot0-9)=-9a\\\\-9a=5\ \ \ |:9\\\\a=-\frac{5}{9}[/tex]
Wzór
[tex]w(x)=-\frac{5}{9}(x^3+x^2-9x-9)=-\frac{5}{9}x^3-\frac{5}{9}x^2+5x+5[/tex]
