6.27.12  Evaluating polynomials: peval polyEval

The peval command evaluates polynomials.
polyEval is a synonym for peval.

• peval takes two arguments:
  • P, a polynomial given by the list of its coefficients.
  • a, a real number.
• peval(P,a) returns the exact or numeric value of P(a), calculated using Horner’s method.

Examples.

• Input:
  peval([1,0,-1],sqrt(2))
  Output:

  √

  2

  √

  2

  −1

  then input:
  normal(sqrt(2)*sqrt(2)-1)
  Output:

  1

• Input:
  peval([1,0,-1],1.4)
  Output:

  0.96