Question

Rezolvati in R ecuatia lg^2(x)+3* lg x+2=0

Answer 1

C. E. : x>0 Notam lg(x) = t => t² + 3t + 2 = 0 Delta = 9-4*1*2 = 1 t1 = (-3+1)/2 = -2/2 = -1 t2 = (-3-1)/2 = -4/2 = -2 Inlocuim => lg(x) = -1 => x = 10^-1 = 1/10 lg(x) = -2 => x = 10^-2 = 1/100 Ambele solutii verifica conditia