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命题不成立! 比如f_n(x)=1/(nx)→0 x_n=1/n→0 但f_n(x_x)=1
[latex]\lim_{n \to \infty }f_n(x)=f(x),\lim_{n \to \infty }x_n=x,[/latex]求证:[latex]\lim_{n \to \infty }f_n(x_n)=f(x).[/latex]
如果f(x)连续。则; [latex]|f_n(x_n)-f(x)|=|f_n(x_n)-f(x_n)+f(x_n)-f(x)|\leq |f_n(x_n)-f(x_n)|+|f(x_n)-f(x)|< \frac{\varepsilon }{2}+\frac{\varepsilon }{2}=\varepsilon .[/latex],
命题不成立!
比如f_n(x)=1/(nx)→0
x_n=1/n→0
但f_n(x_x)=1
[latex]\lim_{n \to \infty }f_n(x)=f(x),\lim_{n \to \infty }x_n=x,[/latex]求证:[latex]\lim_{n \to \infty }f_n(x_n)=f(x).[/latex]
如果f(x)连续。则;
[latex]|f_n(x_n)-f(x)|=|f_n(x_n)-f(x_n)+f(x_n)-f(x)|\leq |f_n(x_n)-f(x_n)|+|f(x_n)-f(x)|< \frac{\varepsilon }{2}+\frac{\varepsilon }{2}=\varepsilon .[/latex],