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MediumCalculusca-172

Bifurcation Parameter Check

Problem

The logistic map has the nonzero fixed point x* = 1 - 1/r for r > 1, with multiplier f'(x*) = 2 - r.

The fixed point is attracting when |2 - r| < 1, that is for 1 < r < 3. Given r, return True when the fixed point is stable and False otherwise.

Hint

At r = 3 the multiplier reaches -1 and the period-doubling cascade begins.

Test cases

case 1
in: [2.5]
expected: true
case 2
in: [3.2]
expected: false
case 3
in: [3]
expected: false
case 4
in: [1.5]
expected: true
case 5
in: [0.5]
expected: false
Starter codePython
def bifurcation_stable(r):
    # Your code here
    pass

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