Final answer:
To simplify the radical √-81 using the product property of radicals, we need to express -81 as the product of two numbers. The simplified form of the radical √-81 is -3i.
Step-by-step explanation:
To simplify the radical √-81 using the product property of radicals, we need to express -81 as the product of two numbers. Since -81 can be written as -9 * 9, we can simplify the radical as follows:
√-81 = √(-9 * 9) = √(-9) * √(9) = i * 3 = -3i
Therefore, the simplified form of the radical √-81 is -3i.