The negative number of d has no square root, so it can be judged that a and b are wrong; And because the result of square root can't be negative, the correct answer is not c, but d.
A the square of any non-zero number is a positive number, and a negative number has no square root, so a can only be 0 < a number >.
C (1) because negative numbers have no square root; ② According to the definition of arithmetic square root, it is known that the arithmetic square root of a number must be a positive number; ③ Because A may be negative, its arithmetic square root is not necessarily A; ④ Because (π-4) is negative; ⑤ The principle is the same as ②.
C suppose the original number is a, and its arithmetic square root is; The expanded number is am, and its arithmetic square root is obviously multiplied.
D it is not difficult to see that a is less than 1. Since the distance between 0 and a is greater than that between 1 and 0, -a is greater than 1. The size is out: a
C suppose a=8, then b=-2. 2 is not the cube root of -8, and -2 is not the cube root of 8, only -2 is the cube root of -8.