1. The problem statement, all variables and given/known data f:ℝ→ℝ x:→sqrt(x^2+1)-lxl 2. Relevant equations calculate f^-1(]0,1]) 3. The attempt at a solution well i chose a y from ]0,1] and tried to find an x that solves the problem like the following. 0<sqrt(x^2+1)-lxl≤1 at the end i got the following: 0<lxl≤1/2 is my work correct?