Which of the following expressions, if any, are equal for all real numbers x
Which of the following expressions, if any, are equal for all real numbers x ?
- I and II only
- I and III only
- II and III only
- I, II, and III
- None of the expressions are equivalent
The correct answer is A.
I. If x is a negative number or positive number, its square will always be positive. The value will be equal to x.
II. Here also, the value will be x as modulus of positive or negative number is always positive.
III. In this case, the result will be negative.