Question

Se x = $\frac{-b + \sqrt{b^{2} - 4ac} }{2a}$, Qual e o valor de x para :
A ) a = 1 b = - 6 c = 8
B) a = 2 b = 10 c = 12

Answer 1

Resposta:

para :

A ) a = 1 b = - 6 c = 8

/\= b^2 - 4ac

/\= (-6)^2 - 4.1.8

/\= 36-32

/\ = 4

x = [- b +/- \/ /\] /2.a

x = [-(-6)+/- \/4]/2.1

x = (6+/- 2)/2

x' = (6+2)/2 = 8/2= 4

x" = (6-2)/2 = 4/2= 2

R.: {2; 4}

B) a = 2 b = 10 c = 12

/\= b^2 - 4ac

/\ = 10^2 - 4.2.12

/\ = 100 - 8.12

/\ = 100 - 96

/\= 4

x = [- b +/- \/ /\] /2.a

x = [ - 10 +/- \/4] /2.2

x = [ -10 +/- 2]/4

x' = (-10-2)/4 = -12/4= - 3

x" = (-10+2)/4= -8/4= - 2

R.: {-2; -3}