4 - (x^2) ≥ 0
Way to do it...
-1( (x^2) - 4 ) ≥ 0
(x^2) - 4 ≤ 0
x^2 ≤ 4
|x| ≤ 2
-2 ≤ x ≤ 2
One question:
1) If this is the best way to do it...why ever factor to make (x-2)(x+2) in any problem (inequality or not)? Doesn't the GMAT warn against directly solving for x in quadratics without factoring?
quadratic inequalities
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- theCodeToGMAT
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It is important to do factorizing so that we may not neglect some possible value:
For example:
x - xy = 0
If we factorize:
x(1-y) = 0
either x = 0 & y = 1
Without Factorizing
x = xy
y = 1 ...
Here, we are left with one lesser value..
For example:
x - xy = 0
If we factorize:
x(1-y) = 0
either x = 0 & y = 1
Without Factorizing
x = xy
y = 1 ...
Here, we are left with one lesser value..
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