Question

Determine os zeros das funçoes
a) f(x)= 6x²+5x-4



b) f(x)= -x²-2x-1

Answer 1

a) 6x²+5x-4=0
∆=b²-4ac
∆=5²-4.6.(-4)
∆=25+96
∆=121
x=-b-/+√∆/2a
x=-5-11/2.6
x=-16/12 (÷4)
x=-4/3
x=-5+11/2.6
x=6/12 (÷6)
x=1/2
S={(-4/3 , 1/2)}
b) -x²-2x-1=0
∆=b²-4ac
∆=(-2)²-4.(-1).(-1)
∆=4-4
∆=0
x=-b-/+√∆/2a
x=-(-2)-0/2.(-1)
x=2-0/(-2)
x=2/(-2)
x=-1
S={-1}