It can be.
No it is not.
Yes.
In mathematics, a radical typically refers to the root of a number, such as the square root. The value under a radical can be negative, but if we're talking about real numbers, the square root of a negative number is not defined in the real number system; instead, it results in an imaginary number. However, if you're considering other radicals, like cube roots, the radical itself can yield a negative result if the number under the radical is negative.
negative
Odd
No it is not.
Yes.
If by "radical" you mean "square root of", then yes. Both square roots of 25 are real numbers.
In mathematics, a radical typically refers to the root of a number, such as the square root. The value under a radical can be negative, but if we're talking about real numbers, the square root of a negative number is not defined in the real number system; instead, it results in an imaginary number. However, if you're considering other radicals, like cube roots, the radical itself can yield a negative result if the number under the radical is negative.
negative
Odd
Not necessarily. If it is the same radical number, then the signs cancel out. Radical 5 times radical 5 equals 5. But if they are different, then you multiply the numbers and leave them under the radical sign. Example: radical 5 * radical 6 = radical 30
I'm not quite sure, but when the number inside the radical (square root sign) is negative, there is a no real-number solution.
A number under a radical sign is known as a radicand.
The number under the radical sign (also known as the radical) is called the radican.
Sure. √6 , the square root of 6, is approximately 2.44949. It's an irrational number --you can't get it as the ratio of any two integers -- but it's real. See Can_a_real_number_be_an_irrational_number
Radical 2 is a number, it does not have a coefficient.