最强大脑第八季片头集数说明

$$\underset{n\to \infty }{\lim }(\sin \frac{2}{n^2}+\sin \frac{4}{n^2}+•••\sin \frac{2n}{n^2})=1$$
∫04arctan⁡4−x4+xdx=2 \int_{0}^{4}\arctan\sqrt{\frac{4-x}{4+x}}dx=2 ∫04​arctan