What is the square root of 0.4?

Apr 15, 2018

$x = \sqrt{0.4} \cong 0.6324 \text{ }$

Explanation:

What method are you allowed to use? My calculator says that $\sqrt{0.4} = 0.632455532$.

Perhaps the number being less than 1 is a problem with your method. So, let

$x = \sqrt{.4} \text{ }$ Then multiply both sides by 2.

$2 \cdot x = 2 \cdot \sqrt{0.4} \text{ }$ Then square the 2 on the left while you bring it inside the radical.

$2 \cdot x = \sqrt{{2}^{2} \cdot 0.4} = \sqrt{4 \cdot 0.4} = \sqrt{1.6} \text{ }$ Then take the square root of 1.6 using your normal method.

I will use my calculator to find the sqrt of 1.6. It is about 1.265. Therefore

$2 \cdot x = 1.265 \text{ }$ Solve for x.

$x = \frac{1.265}{2} \cong 0.6324 \text{ }$

I hope this helps,
Steve