The set of all real values of x for which , is
Correct Answer :
Solution :
The correct option is:
To solve the given inequality, we must eliminate the absolute value. The inequality is:
The expression inside the absolute value is . Since the absolute value function behaves differently depending on whether its argument is positive or negative, we must split the problem into two distinct cases: when and when .
Case 1:
This condition implies that:
Since is non-negative, the absolute value is simply the expression itself: . Substituting this back into our original inequality gives:
Now, distribute the negative sign and simplify:
Taking the square root of both sides, we get:
or
However, we must also satisfy our Case 1 condition, . By intersecting these requirements, the valid interval for Case 1 is:
Case 2:
This condition implies that:
Since is negative in this case, its absolute value is its negation: . Substitute this back into the original inequality:
This simplifies to:
Let's analyze the quadratic equation by checking its discriminant ():
Because the discriminant is negative () and the leading coefficient () is positive, the quadratic expression is strictly greater than for all real numbers .
Thus, the inequality holds true for any value in Case 2. The valid interval here is strictly determined by our case condition:
Combining the Cases
The total solution is the union of the valid intervals from Case 1 and Case 2:
Notice how the boundary perfectly joins the first two sets, simplifying the expression to:
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