How many integer solutions
exist for the equation x2 - 8|x| - 48 =0?
One approach is to solve when x > 0 and then solve for x
< 0. However, there is a slightly simpler method.
Note that x2 is the same as
|x|2, so we can treat the equation as a quadratic in |x|.
(|x| - 12|) (|x| + 4) = 0
|x| could be 12. |x| cannot be -4.
If |x| could be 12, x can be -12 and 12.
Two possible solutions exist.
Labels: CAT - Linear Quadratic Equations Questions and Solutions, CAT 2015, CAT 2016, CAT classes Chennai, CAT Online Classes, CAT Online Coaching, CAT Online Preparation, CAT preparation, CAT Quadratic Equations