Respostas

2013-08-31T21:37:30-03:00
A) f(x) = x² - 7x + 10
Δ = (-7)² - 4.1.10
Δ = 49 - 40
Δ = 9

x = -(-7) +/- √9 / 2.1
x = 7 +/- 3 / 2
x' = 7 + 3 / 2 = 10/2 = 5
x'' = 7 - 3 / 2 = 4/2 = 2

b) f(x) = 4 - x²
x² - 4 = 0
x² = 4
x = √4
x = +/- 2

c) f(x) = x² + 2x + 1
Δ = 2² - 4.1.1
Δ = 4 - 4
Δ = 0

x = -2 +/- √0 / 2.1
x = -2 +/- 0 / 2
x= -2/2
x= -1
                          
Δ = b² - 4.a.c
x = -b +/- √Δ / 2.a
;) Obrigado RafinhaD :)
Por nada ;D