Question

para cada lei de funçao f dada,determine as coordenadas do vertice da parábola correspondente.

a)f(x)=2x^2-5x+3
b)f(x)=-x^2-6x-5
c)f(x)=-x^2+6x-8

Answer 1

a) 2x²-5x+3

∆(-5)²-4.2.3=25-24=1

xv=-b/2a

xv=-(-5)/2.2

xv=5/4

yv=-∆/4a

yv= -1/4.2

yv= -1/8

V=(5/4,-1/8)

b) -x²-6x-5

∆=(-6)²-4.(-1).(-5)=36-20=16

xv=-b/2a

xv=-(-6)/2.(-1)

xv=6/-2

xv=-3

yv= -∆/4a

yv=-16/4.(-1)

yv=-16/-4

yv=4

V=(-3,4)

c) -x²+6x-8

∆=6²-4.(-1)(-8)=36-32=4

xv=-6/2.(-1)

xv=6/2

xv=3

yv=-∆/4a

yv= -4/4.(-1)

yv=-4/-4

yv=1

V=(3,1)