Question

Which two square roots are used to estimate√8?

Answer 1

Answer:

Option C.

Option B.

Step-by-step explanation:

By definition, the square of a number is that number times itself.

The square root of a perfect square is a whole number.

Since the square root of another number (not perfect square) is not a whole number, you can estimate it finding two perfect square roots that number is between.

1) Observe that 4 and 9 are perfect squares:

$4=2^2\\9=3^2$

And 8 is between those numbers.

Therefore, the square roots $\sqrt{4}$ and $\sqrt{9}$ are used to estimage $\sqrt{8}$

2) Notice 36 and 49 are perfect squares:

$36=6^2\\49=7^2$

And 42 is between those numbers.

Therefore, the square roots $\sqrt{36}$ and $\sqrt{49}$ are used to estimage $\sqrt{42}$