/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 1 Solve \(f(x)=0\) for \(x\). $$... [FREE SOLUTION] | 91Ó°ÊÓ

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Solve \(f(x)=0\) for \(x\). $$ f(x)=\sqrt{x-2}-4 $$

Short Answer

Expert verified
The solution for the equation is \(x=18\).

Step by step solution

01

Set the function equal to zero

We're given \(f(x) = \sqrt{x-2}-4\), and we want to solve for \(x\) when \(f(x)=0\). So, we set up the equation: $$ \sqrt{x-2}-4=0 $$
02

Isolate the square root

We want to get the square root by itself on one side of the equation. To do that, we'll add 4 to both sides: $$ \sqrt{x-2}=4 $$
03

Eliminate the square root

Now we want to get rid of the square root. We can do this by squaring both sides of the equation: $$ (\sqrt{x-2})^2=4^2 $$ This simplifies to: $$ x-2=16 $$
04

Solve for x

We can now solve for \(x\) by adding 2 to both sides: $$ x=16+2 $$ So, \(x=18\).
05

Check the solution

We need to verify that our solution is valid, as squaring in step 3 may have introduced extraneous solutions. We'll plug \(x=18\) back into the original equation to see if it holds true: $$ f(18)=\sqrt{18-2}-4 $$ This simplifies to: $$ f(18)=\sqrt{16}-4 $$ And: $$ f(18)=4-4=0 $$ Since \(f(18) = 0\), our solution is valid. Therefore, the solution to the exercise is \(x=18\).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Isolation of Square Roots
When solving equations involving square roots, your first goal is often to isolate the square root expression. This means you want to get the square root term by itself on one side of the equation. Why do we do this? Isolating the square root helps us simplify the equation and makes it easier to remove the radical expression later on.
In our example with the equation \(\sqrt{x-2} - 4 = 0\), starting off by isolating \(\sqrt{x-2}\) is a good first move. We do this by adding 4 to both sides of the equation, yielding \(\sqrt{x-2} = 4\).

This step is crucial because once the square root is isolated, the next steps, like squaring both sides to eliminate the radical, become straightforward. This method is useful in handling various equations involving roots.
Extraneous Solutions
When solving equations, especially those involving square roots, we must be cautious about extraneous solutions. These are solutions that don't actually satisfy the original equation, often appearing because we squared both sides.
Squaring can introduce extra solutions, as seen in the steps when we turned \((\sqrt{x-2})^2 = 4^2\) into \(x - 2 = 16\). This step is perfectly valid but requires checking at the end.
  • Plug the solution back into the original equation.
  • Confirm if both sides of the equation match.
In our problem, we found that \(x=18\) holds true in the original equation, thus verifying it's not extraneous. However, it's essential to do this check to ensure accuracy.
Squaring Both Sides of an Equation
After isolating the square root, the next big move is to square both sides of the equation. This is the trick we use to eliminate the square root and turn a complex equation into a simpler one.
In the equation \(\sqrt{x-2} = 4\), squaring both sides transforms it to \((\sqrt{x-2})^2 = 4^2\), simplifying to \(x - 2 = 16\).

Remember that while squaring helps simplify, it can also bring in extra solutions, hence the need to check your solution at the end. When you encounter square root equations, the pattern is usually to isolate, square, and then solve. Mastering these steps ensures you handle such equations efficiently and correctly.

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