cos -- compute the cosine

• Usage:

  cos x

  cos I

• Inputs:
  • x, a real number
  • I, a real interval
• Outputs:
  • a real number, the cosine of x
  • a real interval, an interval containing the cosines of points of I

i1 : cos 2

o1 = -.4161468365471424

o1 : RR (of precision 53)