Standard functions

The following standard functions (called intrinsic functions in FORTRAN) are available:
exp, log (=ln), log10 (= $^{10}log$), sin, cos, tan, atan (=arctan)
sqrt, abs, min, max
Of course, there are many more.
If the argument is single precision, the result is single precision too. If the argument is double precision, the result is double precision too.
So: exp(1.) is single precision and exp(1d0) is double precision.