Which of the following re-expresses the negative square root −40−−−−√ as a complex number in the standard form a+bi ?(1 point)
1. 4i√10
2. 2√10i
3. 2√10
4. 2i√10
To re-express the negative square root of -40 as a complex number in standard form, we start by simplifying the expression:
-√(-40)
First, we can simplify the expression inside the square root:
√(-1 * 40)
Since the square root of -1 is defined as i, we can write:
i√40
Next, we can simplify the square root of 40:
i√(4 * 10)
Using the property √(ab) = √a * √b, we can write:
2i√10
Therefore, the correct answer is:
4. 2i√10