Question

determine os zeros da funcoes quadraticas f(x)=-x²+2×+3

Answer 1

Olá!

-x²+2x+3=

a=(-1)    b=2  c=3

Δ=b²-4ac
Δ=2²-4*(-1)*3
Δ=4-4*(-3)
Δ=4+12
Δ=16

x= -b+-√Δ/2a
x= -2+-√16/2(-1)
x= -2+-4/(-2)
x'= -2+4/(-2)
x'=2/(-2)
x'= -1
x''= -2-4/(-2)
x''= -6/(-2)
x''=3