Respostas

2013-10-30T21:30:11-02:00
A)  y= x²+5x+8
Δ = b²- 4.a.c
Δ= 25 - 32
Δ= -7                  <--------------------------- PARÁBOLA FLUTUANTE


b)y= -x²+x+6
Δ= b²-4.a.c
Δ= 1+ 24
Δ= 25
x= -1+/- 5 => x1= 2
         2          x2 = -3
         

c)y= x²-10x+9
Δ= b²- 4.a.c
Δ= 100 - 36                        
Δ= 64
x= 10+/- 8 => x1=  9
         2          x2 = 0
Xv= -b/2a => 10/2 = Xv = 5
Yv = -Δ/4a => -64/4 = Yv = -16
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