The following example calculates the square root of various numbers using **sqrt**. Note that if *x* is negative, an indefinite result is returned.

// Explicit forward declaration

doublesqrt(double x); lr_output_message ("Square root of 9 = %f\n",sqrt(9)); lr_output_message ("Square root of 8 = %f\n",sqrt(8)); lr_output_message ("Square root of -8 = %f\n",sqrt(-8));

Example:Output:

Action.c(5): Square root of 9 = 3.000000

Action.c(6): Square root of 8 = 2.828427

Action.c(7): Square root of -8 = -1.#IND00