In pyhton!

We could, in principle, represent a polynomial as a list. For instance, we could write

1+2x−3x2+2x41+2x−3x2+2x4

as

[ 1,2,-3,0,2
where the ith index corresponds to xixi . If we wrote a polynomial this way, we would also like an easy way to evaluate that polynomial for a specified value of xx ; i. e., for x=1.5x=1.5 ,

1+2×1.5−3×1.52+2×1.54=7.3751+2×1.5− 3×1.52+2×1.54=7.375

Compose a function polyeval( coefs, x ) which accepts a list of polynomial coefficients from lowest to highest order (as above) and a value x at which to evaluate the polynomial, and returns a float corresponding to the value of the polynomial evaluated at x.

A good way to start your code would be:

def polyeval( coefs, x ):
value = ??? # an accumulator pattern
# with some kind of loop here
return value
For instance, polyeval( [ 1,1,0,1 ],1 ) (1+x+x31+x+x3 for x=1x=1 ) should return 3.0. polyeval( [ 0,1,0,-2,1 ],-1 ) (x−2x3+x4x−2x3+x4 for x=−1x=−1 ) should return 2.0.