Respostas

2014-05-25T08:53:20-03:00
- x^{2} +x+30
Δ= b²-4ac
Δ=(1)²-4.(-1).30
Δ=1+120
Δ=121

x'= \frac{1+ \sqrt{120} }{2.(-1)} = \frac{-1+11}{2} = \frac{10}{2}=5
x''=  \frac{1- \sqrt{120} }{2.(-1)} = \frac{-1-11}{2}= \frac{-12}{2}=-6
Para y < 0 para - 6 < x < 5