Question

como resolvo y=-3x²+6x+9 funçao de 2 grau

Answer 1

-b +/- raiz de delta / 2a

-6 +- raiz de 6² - 4.(-3).9 / 2 . (-3)

-6 +- raiz de 144 / -6

-6 +- 12 / -6 

x1 -> -6 + 12 / -6 = -1
x2 -> -6 - 12 / -6 = 3

Answer 2

Δ= b²-4.a.c
Δ=6²-4.(-3).9
Δ=36+108=144
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x=-b±√Δ/2a
x=-6±√144/2.(-3)
x=-6±12/-6
x'=-6+12/-6=6/-6=-1
x''=-6-12/-6=-18/-6=3

S={ -1, 3}

bons estudos!! :D