Question

determine caso existam os zero de cada função

a) f(x)=x²-7x+10



b) f(x)=x²-6x+9



c) f(x)=-4x²+4

Answer 1

a) x²-7x+10=0
∆=b²-4ac
∆=(-7)²-4.1.10
∆=49-40
∆=9
x=-b±√∆/2a
x=-(-7)-3/2.1
x=7-3/2
x=4/2
x=2
x=-(-7)+3/2.1
x=7+3/2
x=10/2
x=5
S={(2, 5)}
b) x²-6x+9=0
∆=b²-4ac
∆=(-6)²-4.1.9
∆=36-36
∆=0
x=-b±√∆/2a
x=-(-6)-0/2.1
x=6-0/2
x=6/2
x=3
S={3}
c) -4x²+4=0
∆=b²-4ac
∆=0²-4.(-4).4
∆=0+64
∆=64
x=-b±√∆/2a
x=-0-8/2.(-4)
x=-8/-8
x=1
x=-0+8/2.(-4)
x=8/-8
x=-1
S={(-1, 1)}