13 lines
190 B
C
13 lines
190 B
C
#include <math.h>
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double tanh(double x) {
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int sign = 0;
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if (x < 0) {
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sign = 1;
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x = -x;
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}
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x = expm1(-2 * x);
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x = x / (x + 2);
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return sign ? x : -x;
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}
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