Question

Logaritmi zecimali sa rog dau coronița !!!!!

Answer 1

Răspuns

Explicație pas cu pas:

lg ( x+1) - 2 lg ( x-1) =1 x apartine {1 , + infinit }

lg(x+1) + lg( (x-1) la puterea -2 ) =1

lg ((x+1) x (x-1) la puterea -2 ) =1

lg ( (x+1) x 1/(x-1)² ) = 1

lg ( x+1/x-1²) = 1

x+1/x-1² = e

x+1=e(x-1)²

x-1-e(x²=2x + 1) = 0

x+1-ex²+2ex -2 =0

(1+2e)x+1-ex²-e=0

-ex² +(1+2e) x +1 - e =0

x = -(1+2e)±radical din (1+2e)²+4e x (1-e) /-e x 2