كود

\large f^\prime(x)\ = \lim_{\Delta x\to0}\frac{f(x+\Delta x)-f(x)}{\Delta x}

كود

\Large\hspace{5}\unitlength{1} \picture(175,100){~(50,50){\circle(100)} (1,50){\overbrace{\line(46)}^{4$\;\;a}} (52,50){\line(125)}~(50,52;115;2){\mid}~(52,55){\longleftar[60]} (130,56){\longrightar[35]}~(116,58){r}~(c85,50;80;2){\bullet} (c85,36){3$-q}~(c165,36){3$q} (42,29){\underbrace{\line(32)}_{1$a^2/r\;\;\;}}~}