# Precalculus : Solve Radical Equations

## Example Questions

### Example Question #1 : Solve Radical Equations

Solve for

Possible Answers:

Correct answer:

Explanation:

In order to solve this equation, we need to isolate the radical. In order to do so, we subtract 3 from both sides which leaves us with:

To get rid of the radical, we square both sides:

the radical is then canceled out leaving us with

We solve for  by dividing by 4:

### Example Question #2 : Solve Radical Equations

Solve for

Possible Answers:

Correct answer:

Explanation:

In order to get rid of the radical, we square both sides:

Since the radical cancels out, we're left with

Subtracting both sides by 1 gives us

We then divide both sides by 6 to get

### Example Question #3 : Solve Radical Equations

Which of the following is a solution to the following equation?

Possible Answers:

Correct answer:

Explanation:

We begin by sqaring both sides of the equation.  On the left side, the square root simply disappears, while on the right side we square the term.

We then set the left side equal to 0 by subtracting everything on that side.

We then factor

Therefore,

With problems of this type, it is always wise to double check for any extraneous roots (answers that don't actually work for some reason).  However, in this case both answers work.  Since is the only option among our choices, we should go with it.

### Example Question #4 : Solve Radical Equations

Solve the following radical equation.

Possible Answers:

Correct answer:

Explanation:

When dealing with a radical equation, do the inverse operation to isolate the variable. In this case, the inverse operation of a square root is to square the expression. Thus we square both sides to continue. This yields the following.

### Example Question #5 : Solve Radical Equations

Solve:

Possible Answers:

Correct answer:

Explanation:

1) To remove the radicals, raise both sides of the equation to the second power:

2) To remove the radical, raise both side of the equation to the second power:

3) Now simplify, write as a quadratic equation, and solve:

4) Checking for extraneous solutions.

Plugging in

Plugging in

Since the square root of negative 5.4 gives us an imaginary solution we conclude that the only real solution is x=3.

### Example Question #6 : Solve Radical Equations

Solve the rational equation:

Possible Answers:

Correct answer:

Explanation:

Square both sides to eliminate all radicals:

Multiply both sides by 2:

Combine and isolate x:

### Example Question #7 : Solve Radical Equations

Solve this radical function:

Possible Answers:

None of these answers.

Correct answer:

Explanation:

Add x to both sides:

Square both sides:

Simplify:

Factor and set equal to zero: