1. The problem statement, all variables and given/known data Can [1 - (U^2/W^2)]^(-1/2) equal 0? 2. Relevant equations I don't think the other equations are needed.. This is just a tangent of mine from last Physics' lecture. 3. The attempt at a solution I set the (U/W)^2 part to infinity. 0 = 1 / sqrroot(1 - infinity) which is: 0 = 1 / infinity*i I know (1/infinity) goes to 0, but does the (i) change anything other than make it not real? I'm not worried if it's real or imaginary at the moment.