How Do You Solve Absolute Value Inequalities with Double Variables?

AI Thread Summary
To solve absolute value inequalities with double variables, it's essential to divide the problem into multiple conditions based on the signs of the variables. Typically, there are four conditions to consider: both variables positive, both negative, one positive and one negative. For inequalities like |x| ≤ a, the representation is -a ≤ x ≤ a, which captures both the less than and equal to conditions. The interval solutions will vary depending on the specific conditions applied to x and y. Understanding these regions is crucial for accurately solving the inequalities.
h00zah
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how do you go about solving abs value inequalities with double variables when the abs value bars are on both the variables?

eg; |x| + or - |y| =, >, <, a
 
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I know that when |x| < a it must be -a < x < a, but when |x| "is less than or equal to" a, how do you represent both rules at once?

this is not h.w, we're doing this in class and we haven't been shown how to do this and there are no examples in my text.
 
h00zah said:
but when |x| "is less than or equal to" a, how do you represent both rules at once?
You don't
You divide the problem into n regions/conditions.
In this problem it is four conditions; x and y , positive and negative.

Then the interval solutions depend on the condition/region.

Check out
http://www.purplemath.com/modules/absineq.htm
 
h00zah said:
I know that when |x| < a it must be -a < x < a, but when |x| "is less than or equal to" a, how do you represent both rules at once?
Like this: -a <= x <= a
h00zah said:
this is not h.w, we're doing this in class and we haven't been shown how to do this and there are no examples in my text.
 
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