#### • Class 11 Physics Demo

Explore Related Concepts

# find cube root without calculator

Question:Can any one tell me how to find the cube root using a simple calculator or without any calculator?

Answers:[ The cube root of a number x ] = z, written x^(1/3) = z, implies that number which when cubed produces x. e.g. 8^(1/3) = 2 because 2 cubed = 8 e.g. 27^(1/3) = 3 because 3 cubed = 27 On a simple calculator, you would methodically use trial and error to find cube roots of numbers between 8 and 27; but you would know that those cube roots would be between 2 and 3. You would try 2.5 cubed and see if that was larger or smaller than your number between 8 and 27. If larger, then your next trial would be a number smaller than your trial 2.5, say 2.25 (halfway between 2 and 2.5) etc.

Question:of a number that doesn't have a perfect square root. (it would be a decimal) i also need to know how to find the square root of ANY number without a calculator. i dont know how to do it.

Answers:This site explains three different ways to do it: http://www.homeschoolmath.net/teaching/square-root-algorithm.php

Question:There must be an algebraic method. Find the limit as x approaches 1 of (3 x -1) / ( x - 1) (the cube root of x , minus 1) divided by (the square root of x , minus 1) Interesting responses so far, because the textbook says that the limit is: 2/3 I could find this via a graphing calucator but i was wondering if there is an algebraic method.

Answers:The limit DOES exist: you must use L'Hopital's rule to calculate the limit since it has the form of 0/0. The rule says that the limit of f(x)/g(x) = limit of f'(x)/g'(x). Just find the first order derivatives and you will see that the limit is pretty defined. Thus we have (1/3*x^-2/3)/(1/2*x^-1/2) => 2/3

Question:just starting algebra 2 and theres this question it says place square root 5 on a numberline but i have no idea how to do that without using a calculator some kind of formula or something to help me find root 5 without a calculator will be greatly appreciated

Answers:ask and ye shall receive. http://www.homeschoolmath.net/teaching/square-root-algorithm.php i used to be able to do it, but i'm afraid i've forgotten. i do remember that it's somewhat similar to long division.