Hi, i´m reading Landau´s mechanics and in the 4th chapter in the part disintegration of particles (16) i can´t figure out the following thing. We have a function T=(1/2)m(V2)+(1/2)m(v02) + mVv0cos(θ) , where V and v0 are constant in this problem. We also know the distribution of θ which is (1/2)sinθdθ. The goal is to get a distribution of T. Could you please explain to me how to get it? The book derives it in a way i can´t understand. Thanks in advance.