Solving Equations with Absolute Values and Complex Numbers

Solving Equations with Absolute Values and Complex Numbers

Understanding how to solve equations involving absolute values, particularly in the context of complex numbers, is a fundamental skill in algebra. This article will guide you through solving the equation x^2 - 1 3^2 - 1 and exploring both real and complex solutions.

Simplifying the Equation

Let's start by simplifying the given equation:

Step 1: Simplify the Right Side

First, we calculate the right side of the equation:

32 - 1  9 - 1  8

The equation simplifies to:

x^2 - 1  8

Using Absolute Values

The equation x^2 - 1 8 can be interpreted as an absolute value equation. This can be split into two cases:

Case 1: x^2 - 1 8

Adding 1 to both sides:

x^2  9

Taking the square root of both sides:

x  3 or x  -3

Case 2: x^2 - 1 -8

Similarly, for the second case:

x^2 - 1  -8

Adding 1 to both sides:

x^2  -7

Since x^2 cannot be negative, there are no real solutions from this case.

Final Solutions

The only real solutions to the equation x^2 - 1 8 are:

x  3 and x  -3

Thus, the solutions are x 3 and x -3.

Exploring Complex Solutions

While we have found the real solutions, let's explore the possibility of complex solutions using the equation x^2 - 1 -8:

x^2 - 1  -8

Adding 1 to both sides:

x^2  -7

Now, taking the square root of both sides, we get:

x  isqrt{7}

Therefore, the complete set of solutions includes:

x 3 (real) x -3 (real) x isqrt{7} (complex)

For real numbers, squares are positive, so we can drop the absolute values on both sides, leading to the solutions:

x  -3

If we consider complex numbers, another solution can be x isqrt{11}.

Conclusion

This article has detailed the process of solving the equation x^2 - 1 3^2 - 1, demonstrating both the real and complex solutions. Understanding these concepts is crucial for solving a wide range of algebraic equations and working effectively with complex numbers.