[求助] 积分函数为f(x)*delta(x)*delta(x)，积分域为负无穷到正无穷，等于多少

4楼: Originally posted by feixiaolin at 2014-09-13 07:24:53
f(x)*delta(x)*delta(x)=【f(0)*delta(x)】*delta(x)=f(0)*delta(x)
积分:
Int=f(0)*step(x)   阶跃函数
Int=f(0)           一个数...

2楼: Originally posted by feixiaolin at 2014-09-12 22:55:23
f(x)*delta(x)*delta(x)=【f(0)*delta(x)】*delta(x)=f(0)*delta(x)
积分=f(0)*step(x)   阶跃函数

3楼: Originally posted by hank612 at 2014-09-13 06:53:09
版主大神, 定积分后应该不再是函数, 应该是个数才对.

如果用阶段函数 g_a(x)= 0  if |x|>a/2;  1/a if |x|<=a/2, a为很小的正数
来取代 delta函数, 立得积分值为f(0)/a, 因此a趋于零时,定积分为 ...