(Math with Bittians)
by Dennis Crombie
OSI Certified Open Source Software
(MASM32 assembly source code)

NOPE !!!

rCos and rSin are much faster then fCos and fSin and work with Radian inputs, but...
if you did use Bittians as your main angle type, you'd save time otherwise wasted on conversions.

rCos gives the cosine for Radian input with the use of an FMUL conversion to Bittians, which takes 3 clock cycles more or about 5% more time then bCos which takes Bittian input and doesn't need any conversion.

if 5% more time on every manipulation of every point of every tiangle of every frame would be a good thing, then it's well worth it to use Bittians rather then Radians, if that's not enough to worry about, then rCos and rSin will still speed things along just fine.

as a matter of fact,
with bMath, working in Degrees is the same speed as working in Radians, either one still several times faster then FPU instructions.