SICP exercise 1.08

From Drewiki

Problem

Newton's method for cube roots is based on the fact that if y is an approximation to the cube root of x, then a better approximation is given by the value

Use this formula to implement a cube-root procedure analogous to the square-root procedure from section 1.1.7 of the text.

Solution

Here's a straightforward solution to the problem.

Tests

Output:

2.0000049116755

Output:

3.00000054106418

Output:

4.00001744951074

Output:

5.00000000028793

Output:

4.64159011104646