cosh -- compute the hyperbolic cosine

• Usage:

  cosh x

  cosh I

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

i1 : cosh .2

o1 = 1.020066755619076

o1 : RR (of precision 53)