https://s0.wp.com/latex.php?latex=%5Cdisplaystyle+%5Cint_%7B%7B%5Cbf+R%7D%5Ed%7D+%7Cf_h%28x%29-f%28x%29%7C%5C+dx+%5Cleq+3%5Cvarepsilon&bg=ffffff&fg=000000&s=0