https://s0.wp.com/latex.php?latex=L%28v%29%3D%5Cleft%5C%7B%5Cdfrac%7B1%7D%7B%5Csqrt%7B1-v%5E2%7D%7D%5Cbegin%7Bpmatrix%7D+1+%26+-v%5C%5C+-v+%26+1%5Cend%7Bpmatrix%7D%2F+v%5Cin+%28-1%2C1%29%5Cright%5C%7D&bg=f9f7e1&fg=000000&s=0