Question

Socorrooo




f(x) = 2x² – 3x + 1,

Answer 1

Resposta:

f(x) = 2x² – 3x + 1

2x²-3x+1=0

x'=[3 + √((-3)²-4*2*1)]/(2*2) = [3+√(9-8)]/4=(3+1)/4=1

x''=[3 - √((-3)²-4*2*1)]/(2*2) = [3-√(9-8)]/4=(3-1)/4=1/2

x'=1  e x''=1/2

Observe:

f(x)=ax²+bx+c

x'+x''=-b/a

x'*x''=c/a

no nosso caso 2x²-3x+1=0   ==>a=2 , b=-3  e c=1

x'+x''=-b/a=-(-3)/2=3/2      ...calculamos 1+1/2=3/2

x'*x''=c/a=1/2 ...calculamos  1*1/2 =1/2