Probability theory: let the probability density of random variable X be f (x) = {A / X & # 178;, x > 10; 0, X

Yes, the probability density function integral is 1,
Here is the basic integral formula
The derivative of 1 / X is - 1 / x ^ 2
therefore
∫(10,+∞) a/x^2 dx
=- A / X (substituting upper limit + ∞ and lower limit 10)
=10/x =1
therefore
x=10

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