1. The problem statement, all variables and given/known data 2. Relevant equations F = uR 3. The attempt at a solution I don't understand the followings: For equilibrium at A, the equation should be F1 = T sin [tex]\theta[/tex]. Am I right? While for the one at B, the equation should be F2 = T sin [tex]\theta[/tex]. Am I right? In addition, how can I get cos [tex]\theta[/tex] = (au2 + 1)-0.5 at the last answer? Thank you very much!