How to express natural logarithm ln in C language

In C, the natural logarithm (base e) is represented by the mathematical function log(), which accepts a positive real number and returns its natural logarithm.

Representation of natural logarithm ln in C language

In C language, natural logarithm (with e (base) is represented by the mathematical function log(). This function returns a double-precision floating-point number that is the natural logarithm of the given argument.

Syntax:

<code class="c">double log(double x);</code>

Parameters:

• x - To calculate the natural logarithm of positive real numbers.

Return value: The natural logarithm of

• x, that is, ln(x).

Example:

<code class="c">#include <stdio.h>
#include <math.h>

int main() {
    double x = 2.71828;
    double ln_x = log(x);

    printf("e 的自然对数 (ln(e)) = %lf\n", ln_x);

    return 0;
}</code>

Output:

<code>e 的自然对数 (ln(e)) = 1.000000</code>

Note:

• log() The function only accepts positive real numbers as parameters. Passing a negative number or zero will result in undefined behavior.
• log() The function returns a double precision floating point number, so the results may vary slightly due to rounding errors in floating point operations.

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