What is the square root of 729?

1 Answer
May 23, 2018

The positive square root is 2727 and the negative one -2727.

Explanation:

First find the prime factorisation of 729729:

color(white)(000)729000729
color(white)(000)"/"color(white)(0)"\"000/0\
color(white)(00)3color(white)(00)24300300243
color(white)(00000)"/"color(white)(0)"\"00000/0\
color(white)(0000)3color(white)(000)810000300081
color(white)(0000000)"/"color(white)(00)"\"0000000/00\
color(white)(000000)3color(white)(000)27000000300027
color(white)(000000000)"/"color(white)(00)"\"000000000/00\
color(white)(00000000)3color(white)(0000)900000000300009
color(white)(000000000000)"/"color(white)(0)"\"000000000000/0\
color(white)(00000000000)3color(white)(000)30000000000030003

So:

729 = 3^6729=36

Hence:

sqrt(729) = sqrt(3^6) = 3^3 = 27729=36=33=27

This is the positive square root.

729729 also has a negative square root -2727