Chi函数维基百科,自由的 encyclopedia Chi 函数定义如下[1][2] Chi(x) 2D plot Chi(x) 3D plot C h i ( z ) = ∫ 0 z cosh ( t ) t d t {\displaystyle {\it {Chi}}\left(z\right)=\int _{0}^{z}\!{\frac {\cosh \left(t\right)}{t}}{dt}} C h i ( z ) {\displaystyle Chi(z)} 是下列三阶非线性常微分方程的一个解: z d d z w ( z ) − 2 d 2 d z 2 w ( z ) − z d 3 d z 3 w ( z ) = 0 {\displaystyle z{\frac {d}{dz}}w\left(z\right)-2\,{\frac {d^{2}}{d{z}^{2}}}w\left(z\right)-z{\frac {d^{3}}{d{z}^{3}}}w\left(z\right)=0} 即: w ( z ) = _ C 1 + _ C 2 C h i ( z ) + _ C 3 S h i ( z ) {\displaystyle w\left(z\right)={\it {\_C1}}+{\it {\_C2}}\,{\it {Chi}}\left(z\right)+{\it {\_C3}}\,{\it {Shi}}\left(z\right)}
Chi 函数定义如下[1][2] Chi(x) 2D plot Chi(x) 3D plot C h i ( z ) = ∫ 0 z cosh ( t ) t d t {\displaystyle {\it {Chi}}\left(z\right)=\int _{0}^{z}\!{\frac {\cosh \left(t\right)}{t}}{dt}} C h i ( z ) {\displaystyle Chi(z)} 是下列三阶非线性常微分方程的一个解: z d d z w ( z ) − 2 d 2 d z 2 w ( z ) − z d 3 d z 3 w ( z ) = 0 {\displaystyle z{\frac {d}{dz}}w\left(z\right)-2\,{\frac {d^{2}}{d{z}^{2}}}w\left(z\right)-z{\frac {d^{3}}{d{z}^{3}}}w\left(z\right)=0} 即: w ( z ) = _ C 1 + _ C 2 C h i ( z ) + _ C 3 S h i ( z ) {\displaystyle w\left(z\right)={\it {\_C1}}+{\it {\_C2}}\,{\it {Chi}}\left(z\right)+{\it {\_C3}}\,{\it {Shi}}\left(z\right)}