# Question: Let X be N 0 1 Find the pdf of Y

Let X be N(0, 1). Find the pdf of Y = |X|, a distribution that is often called the half-normal. Hint: Here y ∈ S y = {y : 0 < y < ∞}. Consider the two transformations x1 = −y, −∞ < x1 < 0, and x2 = y, 0 < y < ∞.

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