Square root of squares ...

richs_ca wrote:If X<0 then sq rt of -X \x\ is (note: \x\ is absolute value of x, not sure how to make the propoer symbol.)

I thought the answer was X. X is negative and it asks for the sq rt of -X, so -(-X) is X. And X times the absolute value of X is X*X which is X^2, and the sq rt of that is X.

But it tells me that the answer is -X. What am I missing?

Stuart Kovinsky wrote:

richs_ca wrote:If X<0 then sq rt of -X \x\ is (note: \x\ is absolute value of x, not sure how to make the propoer symbol.)

I thought the answer was X. X is negative and it asks for the sq rt of -X, so -(-X) is X. And X times the absolute value of X is X*X which is X^2, and the sq rt of that is X.

But it tells me that the answer is -X. What am I missing?

X is negative and sqrtX is defined as the postive root of X.

So, since the correct answer is positive, and X is negative, we need to multiply X by -1 to make it positive.

In other words, -1(x) = positive number