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Solve for x |x| = 4 ​

User Elmart
by
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1 Answer

2 votes

Answer:

x = 2

Explanation:

You want the value of x that satisfies x|x| = 4.

Domain

The absolute value function splits the domain of the equation into two parts.

For x < 0, the equation is ...

x(-x) = 4

x² = -4

There are no real solutions in this domain.

For x ≥ 0, the equation is ...

x² = 4

x = √4 = 2

The only solution is x = 2.

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Additional comment

In the attachment, we have rewritten the equation to ...

x|x| -4 = 0

The graphing calculator readily identifies x-intercepts, so this is a convenient way to find the solution. You will notice that for x < 0, the graph is of -x²-4, which is never zero.

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Solve for x |x| = 4 ​-example-1
User Tlaminator
by
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