Question

Resolva as funções: A) - x elevado a 2 + x + 12 B) - x elevado a 2 + 6 × - 5 C) 6× elevado a 2 + × -1 D) 3x elevado a 2 - 7 × + 2

Answer 1

A) -x²+x+12

∆= 1²-4.(-1).12
∆= 1 + 48
∆= 49

X= -1+-√49/2.(-1)
x= -1+-7/-2

x'= -1+7/-2 = 6/-2 = -3
x"= -1-7/-2 = -8/-2 = 4

B) -x²+6x-5

∆= 6²-4.(-1).(-5)
∆= 36-20
∆= 16

x= -6+-√16/2.(-1)
x= -6+-4/-2

x'= -6+4/-2 = -2/-2 = 1
x"= -6-4/-2 = -10/-2 = 5

C) 6x²+x-1

∆= 1²-4.6.(-1)
∆= 1 + 24
∆= 25

x= -1+-√25/2.6
x= -1+-5/12

x'= -1+5/12 = 4/12 = 0,33...
x"= -1-5/12 = -6/12 = 0,5

D) 3x²-7x+2

∆= (-7)²-4.3.2
∆= 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 = 0,33...

Espero ter ajudado....