Question

Dada a função real f(x)=-X² + 2 X +3

Answer 1

f(x)= -x²+2x+3

-x² +2x +3=0
x²-2x-3=0

a=1
b=-2
c=-3
Δ=b²-4ac
Δ=(-2)²-4(1)(-3)
Δ=4+12
Δ=16

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

f(x)=3
f(x)=-1