- #1
izelkay
- 115
- 3
Homework Statement
If X is uniformly distributed over (0,1), find the PDF of Y = |X| and Z = e^X
Focusing on the |X| one
Homework Equations
Derivative of CDF is the PDF
The Attempt at a Solution
So I start by writing down the CDF of X, Fx(x):
0 for x <0
x for 0 ≤ x ≤ 1
1 for x ≥ 1
And I also know the range of Y = |X| is [0,1]
Finding the CDF of Y:
FY(y) = P(Y≤y)
=
P(|X|≤y)
=
P(-y ≤ X ≤ y)
=
Fx(y) - Fx(-y)
So
FY(y) = Fx(y) - Fx(-y)
But the range of Y is [0,1] so I can get rid of the Fx(-y) and have
FY(y) = Fx(y) = y
So the CDF of Y is then
0 for y < 0
y for 0 ≤ y ≤ 1
1 for y≥1
To find the PDF, I can just take the derivative and have
1 for 0 ≤ y ≤ 1
0 otherwise
Is this correct?