cmath

  abs()       -  absolute value 

  floor()      -  largest integer, not greater than

  ceil()       -  smallest integer, no less than

  sin() asin()   -   -π/2 ~ π/2

  cos() acos()  -   0 ~ π

  tan() atan()     

  tan2(y,x)      -   -π ~ π

  log()        -  natural (base e) logarithm

  log10()     -  base 10 logarithm

  pow()       - base raised to the expth power

  sqrt()       -  the square root 

   

    ex)  pow((double)5, (double)3)

          = 5^3 = 125