The square root of 21 is not an integer. The concepts of "even" vs. "odd" is only defined for integers.
Neither.
The square root of 21 is 4.58257569495584.
The square root of 21 is 4.58257569495584.
It is odd.
4.6 is a better approximation to the square root of 21.
It is odd.
21
All non-even numbers are odd. All squares of even numbers are even. All squares of odd numbers are odd. Therefore all numbers which are odd and not the square of an odd number are the solution set. It contains: {3, 5, 7, 11, 13, 15, 17, 19, 21, 23, 27, 29, 31, ...}
Root 64 is 8, if by root you mean the square root. Then the problem become -square root 84(6+8) which is the - square root of 84(14) But square root of 84 is 2(square root of 21) so the final answer comes from -2(square root 21)x14 which is -28square root (21)
21The square root of 441 is 21
Your answer is: 17.7482393
The square root and square functions are inverse of one another EXCEPT that square root is not really a function: it is a 1-to-many mapping. So sqrt(square(21)) = sqrt(441) = ±21
21 is an odd composite number