Question

Determine as raízes das funções qudrática:

a) f(x) = x² - 8x + 12

b) f(x) = x² - 10x + 25​

Answer 1

a) f(x) = x² - 8x + 12

a=1

b=-8

c=12

∆=b²-4.a.c

∆=(-8)²-4.(1).(12)

∆=64-48

∆=16

x'=[-(-8)+√16]/2.(1)

x'=[8+4]/2

x'=12/2

x'=6

x"=[-(-8)-√16]/2.(1)

x"=[8-4]/2

x"=4/2

x"=2

As raízes serão : 2 e 6

b) f(x) = x² - 10x + 25

a=1

b=-10

c=+25

∆=b²-4.a.c

∆=(-10)²-4.(1).(25)

∆=100-100

∆=0

x'=x"=-b/2a

x'=x"=-(-10)/2.(1)

x'=x"=10/2=5

As raízes serão : 5 e 5