Final answer:
To express a radical using the imaginary unit i, any negative square root is expressed in terms of i. For instance, √-90 is expressed as i√90, and 3√-10 becomes 3i√10. option b.
Step-by-step explanation:
The information provided does not directly pertain to expressing the radical using the imaginary unit i. However, I can explain how to express radicals using the imaginary unit i. The imaginary unit i is defined as the square root of -1. To express a radical with an imaginary unit, any negative square root is expressed in terms of i.
For example:
- If we have √-90, we can express this as √90 × √-1, which simplifies to √90 × i, or i√90.
- For 3√-10, we follow a similar process, expressing it as 3√10 × √i, which simplifies to 3i√10.
Values that are already multiplied by i, such as i times 9 or 90 times i, do not have to be manipulated, as they do not contain a radical.