173k views
5 votes
R^{2} =8 solving equations using square roots

User TutuDajuju
by
8.3k points

1 Answer

3 votes

Answer:


r=\pm\,2\sqrt2

Explanation:

Given the equation:


r^2=8,

we can solve for
r by taking the square root of both sides.


√(r^2)=\pm√(8)

But, we must remember the even root property, which states that if
x^2 = a, where
a is a non-negative real number, then
x = \pm \sqrt a, because both
(-a)^2 and
a^2 result in
a.

______________

For example, if you want to find the square root of 25, you know that 5 × 5 = 25, so
√(25) = 5. However, (-5) × (-5) also equals 25, so (-5) is also a valid solution for
√(25).

‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾


r=\pm√(8)

Now, we can simplify the square root by prime factoring it.


r=\pm√(2 \cdot 2\cdot2)

We can see that there is one complete pair of 2's, so we can take those out of the square root.


\boxed{r=\pm\, 2\sqrt2}

User Marianna
by
8.3k points