Question

What is the sum of ..

Answer 1

For this case, we must add two negative roots:

$\sqrt {-2} + \sqrt {-18}$

By definition, we know that:

$i = \sqrt {-1}$

$i^2=-1$

So:

$\sqrt {-2} = \sqrt {2i ^ 2} = i \sqrt {2}\\\sqrt {-18} = \sqrt {18i ^ 2} = i \sqrt {18}$

Also:

$\sqrt {18} = \sqrt {9 * 2} = \sqrt {2 * 3 ^ 2} = 3 \sqrt {2}$

So, we have:

$i \sqrt {18} = 3i \sqrt {2}$

So, we have:

$\sqrt {-2} + \sqrt {-18} = i \sqrt {2} + 3i \sqrt {2} = 4i \sqrt {2} = 4 \sqrt {2} i$

Answer:

Option b

Answer 2

Answer:

4i√2

Step-by-step explanation:

you add it with a calculator

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