i 2 α β {\displaystyle i^{2}\alpha \beta } i 2 {\displaystyle i^{2}} x 2 + y 2 = x 2 + y 2 + 2 x y {\displaystyle x^{2}+y^{2}=x^{2}+y^{2}+2xy} i {\displaystyle {\sqrt {i}}} 1 2 {\displaystyle {\frac {1}{2}}} H 2 O {\displaystyle H_{2}O} C H 2 O H {\displaystyle CH_{2}OH}
d 2 y d X + W 2 Y = O {\displaystyle {\frac {d^{2}y}{dX}}+W^{2}Y=O}
T = 2 π l g {\displaystyle T=2\pi {\sqrt {\frac {l}{g}}}}
d 2 y d t 2 + 2 b d y d t + w 2 y = p sin ( w t ) {\displaystyle {\frac {d^{2}y}{dt^{2}}}+2b{\frac {dy}{dt}}+w^{2}y=p\sin(wt)} H2SO4
