What is the square root of 4?

1 Answer
Sep 6, 2015

2 and -2 are square roots of 4. The principal square root of #4#, (denoted #sqrt4#) is #2#

Explanation:

A number is a square root of 4 is, when multiplied by itself, the result is 4.

In notation: #n# is a square root of #4# if #n^2 = n xx n = 4#

There are two numbers that will work #2 xx 2 = 4# and also #-2 xx -2 = 4# so the numbers #2# and #-2# are square roots of #4#. When people talk about the square root of #4#, they usually mean the number whose complete name is "the principal square root of #4#.

The principal square root of a (positive) number is the non-negative square root. The symbol #sqrt_ # denoted the principal square root.

So #sqrt4 = 2#

Here on Socratic to type #sqrt4# use the hashtag # before and after sqrt4. I you want some arithmetic under the square root symbol, use parentheses:

no parentheses: hashtag sqrt9+16 hashtag gets #sqrt9+16#

With parentheses hashtag sqrt(9+16) hashtag gets #sqrt(9+16)#