Respostas

2013-12-05T11:26:47-02:00
A)
x²-4x+2 = 0
Δ = b²-4ac
Δ = (-4)²-4.1.2
Δ = 16-8
Δ = 8
x = (-b+/-√Δ)2a
x = [-(-4)+/-√8]/2
x = (4+/-2√2)/2
x' = (4+2√2)/2 --> x' = 2+√2
x" = (4-2√2)/2 --> x" = 2-√2
2 4 2