Question

determine o zero da função f (x) 2x ao quadrado +3x -9

Answer 1

y = 2x²+3x-9 = 0
a= 2 b= 3 c= -9
Δ=b²-4.a.c
Δ=3²-4.2.(-9)
Δ=9+72
Δ=81

x=-b±√Δ / 2.a ⇒ -3±√81 / 2.2 ⇒ -3±√9 / 4

x1=-3+9 = 6 / 4 = 1,5
x2=-3-9 = -12 / 4 = -3