How to find the cube root of a number?
There is a way of calculating a cube root without pressing the cube root button, based on making a first reasonable guess and then using a particular formula several times to get a closer answer. Say you want to find the cube root of 45. The cube of 3 is 27 and the cube of 4 is 64, so the answer is between 3 and 4. Let us start with 3.5. Put 3.5 instead of x in the formula x – (x^3-45) / (3x^2) The result is 3.55782. Now put that value into the formula instead of x, to get 3.55689. You only have to do this 2 or 3 times to get an extremely accurate cube root. If you want to do another cube root, say of 96, put 96 in the formula instead of 45, and start with a number between 4 and 5.
