( x +√x²-1 ) · ( x - √x²-1 ) = x² - (√x²-1) ² = x² - x² +1 = 1
2 =2·1 = 2 ·√(x +√x²-1 ) ·( √x - √x²-1 )
conditie x² - 1 ≥ 0 ⇒ x∈ ( - ∞ , -1 ] U [ 1 , +∞)
notam rad. cu t
t + 1 /t = 2 ; t² -2t + 1 = 0 ; ( t -1 )² =0 ; t =1
rad . ²⁰¹³√x +√x²-1 = 1
x + √x²-1 =1
x -1 + √x²-1 =0 ; √( x -1)² +√x²-1 = 0
√(x-1) · [√(x-1 ) + √(x +1) ] =0 daca x-1=0 ; x =1
poz +poz ≠ 0
S= 1
