If k^2 = m^2, which of the following must be not true or false?
Choose the correct choice from the following answers.
A) k = m B) k = −m C) k = |m| D) k = −|m| E) A,B,C,D FALSE
Since k^2=m^2 we have 0=k^2 – m^2 =(k-m)*(k+m). So k=m or k=-m.   So only (A) and only (B) cannot be an answer.   The choice (C) tells us that k should be greater than or equal to 0.   Similarly the choice (D) tells us that k should be less than or equal to 0.   So neither (C) nor (D) cannot be the answer.   The answer is, therefore, (A,B,C,D FALSE).
<result>E</result>
If k^2 = m^2, which of the following must be not true or false?