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


expr {exp(1)}       ;# e
expr {4 * atan(1)}  ;# pi -- also, simpler: expr acos(-1)
expr {sqrt($x)}     ;# square root
expr {log($x)}      ;# natural logarithm, also log10
expr {exp($x)}      ;# exponential
expr {abs($x)}      ;# absolute value
expr {floor($x)}    ;# floor
expr {ceil($x)}     ;# ceiling
expr {$x**$y}       ;# power, also pow($x,$y)