Solving Radical Inequalities
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$$2 - \frac{2x}{3} \geq \sqrt{x + 4}$$
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Step by Step Written Solution
In this exercise, we'll solve a radical inequality. We are given two minus two x over three is greater than or equal to the square root of x plus four.
Solving a Radical Inequality
Solving radical inequalities requires two main considerations: identifying the domain for which the root is defined, and ensuring both sides are handled correctly when squaring.
1. Domain Constraint
The term inside the square root must be non-negative.
So, x plus four must be greater than or equal to zero.
By subtracting four from both sides, our first condition is that x must be greater than or equal to negative four.
Now, notice that the square root is always non-negative. For the left side to be greater than or equal to it, the left side must also be non-negative.
2. Sign Constraint
We rearrange this to isolate x. Multiplying by three, we get six minus two x is greater than or equal to zero.
Then, six is greater than or equal to two x, which means x must be less than or equal to three.
With our domain and sign constraints established, we can safely square both sides of the original inequality.
Squaring the Inequality
Constraints: $-4 \leq x \leq 3$
Let's expand the left side using the binomial square formula.
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