Question #02059

2 Answers
Sep 21, 2017

3sqrt(2) = 4.24264068712

Explanation:

The number 18 can be written as 9*2. Thus sqrt(18) = sqrt(9*2).

sqrt(9*2) can also be writted as sqrt(9) * sqrt(2), and since sqrt(9) = 3, sqrt(18) = 3*sqrt(2) = 3sqrt(2).

Sep 22, 2017

3sqrt(2)

Explanation:

The square root of 18 is an irrational number so it is common to express this in the form asqrt(b). This is known as a simplified surd.

For sqrt(18) notice we can factor the number inside the radical ( this is properly called the radicand):

So sqrt(18) => sqrt( 2 xx 9)

Since 9 is an exact square we can extract the root and put the root before the radical.

3sqrt(2)

The root of 2 is irrational so we leave it.