Respostas

2013-12-05T18:49:31-02:00
1)

x²+4x=0
x(x+4)=0
x'→ 0
x''=-4

2 )

x²-16x=0
x(x-16)=0
x'→ 0
x''→ 16

3 )

x^2-8x+12=0\\\Delta=(-8)^2-4.1.12\\\Delta=64-48\\\Delta=16

x= \frac{8\pm4}{2} \\
\\x_1=6\\
\\x_2=2
2 5 2