Final answer:
To express the radical ± s√ (-66) with the imaginary unit i, simplify the expression to ±(√66i), noting that there are both positive and negative solutions.
Step-by-step explanation:
To express the radical ± s√ (-66) using the imaginary unit i, we first need to recognize that the square root of any negative number is a multiple of i. The number 66 is positive, so we take its square root as usual. Then, we multiply it by i to account for the original negative sign under the radical. Therefore, the expression simplifies to ±√66i. The ± indicates that there are both positive and negative solutions, so the final expression is ±(√66i).