Question

√x+6=x
Me ajudem nessa equacao irracional

Answer 1

√x + 6 = x (√x + 6)^2 = x^2 x + 6 = x^2 x^2 = x + 6 x^2 - x - 6 = 0 ∆ = b^2 - 4ac ∆ = (-1)^2 - 4.1.(-6) ∆ = 1 + 24 ∆ = 25 x = (-b +-√∆)/2a x = (-(-1) +-√25)/2a x = (1 +-5)/2 x' = (1 + 5)/2 = 6/2 = 3 x" = (1 - 5)/2 = -4/2 = -2 Provando: x' = 3 √x + 6 = x √3 + 6 = 3 √9 = 3 3 = 3 (verdadeira) x" = -2 √x + 6 = x √-2 + 6 = -2 √4 = -2 2 = -2 (falsa) V = {3}