EasyCalculusca-103

Chebyshev Polynomial Value

Problem

Evaluate the Chebyshev polynomial of the first kind T_n(x) with the recurrence:

T_0 = 1, T_1 = x, T_{k+1} = 2 * x * T_k - T_{k-1}

Assume n >= 0.

Hint

On [-1, 1] this equals cos(n * arccos(x)), and T_n(-1) = (-1)^n.

case 1

in: [0,0.3]

expected: 1

case 2

in: [2,0.5]

expected: -0.5

case 3

in: [3,0]

expected: 0

case 4

in: [4,1]

expected: 1

case 5

in: [5,-1]

expected: -1

Starter codePython

def chebyshev_t(n, x):
    # Your code here
    pass

5 test cases · run your code against them in the editor