219. [latex]W(x)=(x+2)^2(ax^2+bx+c)[/latex] [latex]W(0)=24\(0+2)^2(acdot0^2+bcdot0+c)=24\4c=24\c=6[/latex] [latex]W(1)=27\(1+2)^2(acdot1^2+bcdot1+6)=27\9(a+b+6)=27\a+b+6=3\a+b=-3[/latex] [latex]W(-3)=27\(-3+2)^2(acdot(-3)^2+bcdot(-3)+6)=27\9a-3b+6=27\9a-3b=21\3a-b=7[/latex] [latex]b=-3-a\3a+3+a=7\4a=4\a=1\b=-3-1=-4[/latex] [latex]W(x)=(x+2)^2(x^2-4x+6)=(x^2+4x+4)(x^2-4x+6)=\=x^4-4x^3+6x^2+4x^3-16x^2+24x+4x^2-16x+24=\=x^4-6x^2+8x+24[/latex] 221. [latex]W(x)=ax^2(x-2sqrt{2})(x+2sqrt{2})=ax^2(x^2-8)[/latex] [latex]W(2)=-4\acdot2^2(2^2-8)=-4\4a(-4)=-4\4a=1\a=frac{1}{4}[/latex] [latex]W(x)=frac{1}{4}x^2(x^2-8)=frac{1}{4}x^4-2x^2[/latex] b) [latex]W(x)=-3\frac{1}{4}x^4-2x^2=-3\frac{1}{4}x^4-2x^2+3=0\Delta=4-3=1\x^2=frac{2-1}{frac{1}{2}}=2 vee x_2=frac{2+1}{frac{1}{2}}=6[/latex]
