Respostas

2014-08-04T19:54:38-03:00
A) y=x²-3x
Resolvendo por Bháskara:
Δ = (-3)²-4.1.0   
Δ = 9-0
Δ=9
------
x= -(-3)±√9/2.1
x= 3
±3/2
x1=3
x²=0

S = {0;3}
_________________
b)y=x²-4
Bháskara:
Δ=(0)²-4.1.4
Δ=0-16
Δ=16
--------
x=-0±√16/2.1
x=0±4/2
x1=2
x²=-2

S = {-2;2}


       
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