The ReLU activation function is defined as
Amax(x, 0)
B1 / (1 + exp(-x))
Ctanh(x)
Dexp(-x)
Answer & Solution
Correct answer: A. max(x, 0)
ReLU(x) = max(x, 0) — keep positive values, zero out negatives. Simple, fast, and the dominant activation in modern hidden layers.
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