Question

Determine os zeros das funções abaixo.
a) f(x) = x2 - 5x + 6
b) f(x) = 3x2 - 7x + 2
c) f(x) = x2

Answer 1

a)f(X)=x²-5x+6=0

∆=b²-4.ac
∆=(-5)²-4.1.6
∆=25-24
∆=1

x=-b±√∆:2.a
x=5±√1:2.1
x=5±1:2

x'=5+1:2=6:2=3
x''=5-1:2=4:2=2

b)f(x)=3x²-7x+2=0

∆=-7²-4.3.2
∆=49-24
∆=25

x=7±√25:2.3
x=7±5:6

x'=7+5:6=12:6=2
x"=7-5:6=2:6=⅓

c)f(x)=x²=0
x=√0
x=0