Final answer:
The student's question involves calculating the square root of a negative number, which introduces the concept of imaginary numbers represented by the unit ‘i’. The solution for the square root of −-49 is 7i, multiplied by −-3 gives us −-21i.
Step-by-step explanation:
The student is asking for the square root of the product of two numbers, where one of them is another square root of a negative number, specifically −-3 radical −-49.
In mathematics, the square root of a negative number involves imaginary numbers. The square root of −-49 can be expressed using the imaginary unit i, where i is the square root of −-1.
The solution to −-49 under a square root is 7i. When combining this with the other number −-3, we could write the expression as −-3 * 7i or −-21i.
The critical aspect for the student is to understand the role of i in representing the square root of negative numbers and how to carry out multiplication involving imaginary numbers.