Task

Show how to use the following math constants and functions in your language   (if not available, note it):

   e   (base of the natural logarithm)
   



π


{\displaystyle \pi }


   square root
   logarithm   (any base allowed)
   exponential   (ex )
   absolute value   (a.k.a. "magnitude")
   floor   (largest integer less than or equal to this number--not the same as truncate or int)
   ceiling   (smallest integer not less than this number--not the same as round up)
   power   (xy )


Related task

   Trigonometric Functions


/* e  not available other than by using exp(1q0).*/
/* pi not available other than by using a trig function such as: pi=4*atan(1) */
y = sqrt(x);
y = log(x);
y = log2(x);
y = log10(x);
y = exp(x);
y = abs(x);
y = floor(x);
y = ceil(x);
a = x**y;      /* power */
/* extra functions: */
y = erf(x);    /* the error function. */
y = erfc(x);   /* the error function complemented. */
y = gamma (x);
y = loggamma (x);