作业帮 > 数学 > 作业

极限与变积分上限问题

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/04/29 14:55:05
极限与变积分上限问题
做变换 u=x²-t²,则极限
  g.e = (1/2)lim(x→0)∫[0,x]f(x²-t²)d(t²)/(x^4)
    = (-1/2)lim(x→0)∫[x²,0]f(u)du/(x^4)
    = (1/2)lim(x→0)∫[0,x²]f(u)du/(x^4) (0/0)
    = (1/2)lim(x→0)[f(x²)(2x)]/(4x^3)
    = (1/4)lim(x→0)[f(x²)-f(0)]/(x²)
    = (1/4)f'(0)
    = 1/4.