If x<0, then (-x*│x│)^1/2 is
A -x
B -1
C 1
D x
E x^1/2
IMO D. But the OA is A. Pls explain. Thanks.
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Right. Or you could sayjay2007 wrote:Let a = -x say.
(-x*|x|) = (a*a)^1/2
= a
= -x.
Therefore answer = A.
Pls. correct me if i am wrong.
since x<0, we know that |x| = -x [ie |-3| = -(-3) = 3]
thus we have
(-x * -x )^1/2
((-x)^2)^1/2
(-x)^1/2 * 2
-x^1
-x
by rule of exponents