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 Summary ```#include <80c517.h> float log10517 ( float val); /* value to take common logarithm of */ ``` Description The log10517 function calculates the common logarithm for the floating-point number val. The logarithm is the exponent to which the base (10 in the case of common logs) must be raised to equal val. Or, log10 10x = val For example, log10517(120) = log10517(102 × 1.2) = 2 + log10517(1.2) ≈ 2 + 0.079181 or 2.079181 Note This routine uses the arithmetic unit of the Infineon C517x/C509 to provide accelerated execution speed. Do not use this routine with a CPU that does not support this feature. Return Value The log10517 function returns the floating-point common logarithm of val. If x < 0, log10517 returns NaN. If x = 0, log10517 returns -INF. See Also Example ```#include <80c517.h> #include /* for printf */ void tst_log10517 (void) { float x; float y; x = 2.718282; x *= x; y = log10517 (x); /* y = 2 */ printf ("LOG10517(%f) = %f\n", x, y); } ```

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