Find the sum of 4, square root of, 2, end square root4

2

and 2, square root of, 8, end square root2
8

in simplest form. Also, determine whether the result is rational or irrational and explain your answer.

1 answer

To find the sum of \(\sqrt{4}\) and \(2\sqrt{8}\), let's compute each term separately.

  1. Calculate \(\sqrt{4}\): \[ \sqrt{4} = 2 \]

  2. Calculate \(2\sqrt{8}\): We first simplify \(\sqrt{8}\): \[ \sqrt{8} = \sqrt{4 \cdot 2} = \sqrt{4} \cdot \sqrt{2} = 2\sqrt{2} \] Now, substitute back into \(2\sqrt{8}\): \[ 2\sqrt{8} = 2 \cdot 2\sqrt{2} = 4\sqrt{2} \]

  3. Now, we sum \(\sqrt{4}\) and \(2\sqrt{8}\): \[ \sqrt{4} + 2\sqrt{8} = 2 + 4\sqrt{2} \]

Thus, the sum in simplified form is: \[ 2 + 4\sqrt{2} \]

Next, we determine if the result \(2 + 4\sqrt{2}\) is rational or irrational.

The number \(4\sqrt{2}\) is irrational, because \(\sqrt{2}\) is an irrational number, and multiplying an irrational number by a non-zero rational number (in this case, 4) still results in an irrational number. The sum of a rational number (2) and an irrational number (\(4\sqrt{2}\)) is always irrational.

Thus, the final answer is: \[ \text{The sum is } 2 + 4\sqrt{2}, \text{ which is irrational.} \]