Question

概率密度求解设随机变量X的概率密度为f(x)=a/x2,x>10 0,x

Answer 1

∫[-∞,+∞]f(x)dx=1,

∫[-∞,+∞]f(x)dx=∫[10,+∞]a/x^2dx

=-a/x|[10,+∞]

=a/10

=1,

a=10.