https://s0.wp.com/latex.php?latex=%5Cint%7B%5Ccos+%5Cleft%28+2x+%5Cright%29dx%3D%5Ctfrac%7B1%7D%7B2%7D%5Cint%7B%5Ccos+%5Cleft%28+2x+%5Cright%29%5Cleft%28+2dx+%5Cright%29%7D%7D%3D%5Ctfrac%7B1%7D%7B2%7D%5Csin+%5Cleft%28+2x+%5Cright%29%2BC&bg=ffffff&fg=333333&s=0&c=20201002