Problem 35

Question

\(31-42\) . Solve the equation both algebraically and graphically. $$ x^{2}-32=0 $$

Step-by-Step Solution

Verified
Answer
The solutions are \(x = 4\sqrt{2}\) and \(x = -4\sqrt{2}\).
1Step 1: Understand the Equation
The given equation is a quadratic equation: \(x^2 - 32 = 0\). Our task is to find the values of \(x\) that satisfy this equation.
2Step 2: Solve Algebraically
To solve \(x^2 - 32 = 0\) algebraically, add 32 to both sides of the equation: \(x^2 = 32\). Next, take the square root of both sides: \(x = \pm \sqrt{32}\). Simplifying \(\sqrt{32}\) gives \(\sqrt{16 \times 2} = \sqrt{16} \times \sqrt{2} = 4\sqrt{2}\). Therefore, \(x = \pm 4\sqrt{2}\).
3Step 3: Graphically Interpret the Solution
The equation \(x^2 - 32 = 0\) can be thought of as the function \(f(x) = x^2 - 32\). To find the solution graphically, plot \(y = x^2 - 32\) and identify where the graph crosses the x-axis. These points are \(x = 4\sqrt{2}\) and \(x = -4\sqrt{2}\), confirming the solutions found algebraically.

Key Concepts

Algebraic SolutionGraphical SolutionSquare Root Simplification
Algebraic Solution
Solving a quadratic equation algebraically involves manipulating the equation to uncover its roots, which are the values of \(x\) that satisfy the equation. Here, we have the quadratic equation \(x^2 - 32 = 0\). The aim is to isolate \(x\) and find its possible values.

First, you'll want to balance the equation by adding 32 to both sides, resulting in \(x^2 = 32\). To simplify further, take the square root of both sides of the equation. This operation leads to two possible solutions due to the nature of square roots, giving you \(x = \pm \sqrt{32}\).

Now, let's simplify \(\sqrt{32}\). You can express it as \(\sqrt{16 \times 2}\), which breaks down to \(\sqrt{16} \times \sqrt{2}\). Since \(\sqrt{16} = 4\), you get \(x = \pm 4\sqrt{2}\). These are the solutions found using the algebraic method.
Graphical Solution
Graphical solutions provide a visual method to understand where the roots of an equation lie. This approach involves plotting a function on a graph and observing its intersections with the x-axis. For our equation \(x^2 - 32 = 0\), we can treat it as a function, \(f(x) = x^2 - 32\).

When you graph \(y = x^2 - 32\), you will look for the x-values where the curve crosses the x-axis. These intersections represent the solutions to the equation. In this exercise, the graph will cross the x-axis at \(x = 4\sqrt{2}\) and \(x = -4\sqrt{2}\).

Plotting functions like this is very useful because it provides an immediate way to visualize the solutions. Often, it can also illustrate complex or irrational roots in a clear, intuitive manner.
Square Root Simplification
Square root simplification is an important skill in algebra that helps in deriving clean and exact solutions for quadratic equations. In this example, simplifying \(\sqrt{32}\) was a vital step. Let's break this down.

Square roots can often be simplified by writing the number under the root as a product of a perfect square and another factor. For \(\sqrt{32}\), we identify the factors \(32 = 16 \times 2\). Here, 16 is a perfect square.

Thus, \(\sqrt{32}\) becomes \(\sqrt{16} \times \sqrt{2}\), simplifying further to \(4\sqrt{2}\) since \(\sqrt{16} = 4\). Simplifying radicals like this not only makes your final answer simpler but also aids in clearer communication of mathematical solutions.

By mastering square root simplification, you ensure the solutions are as exact as possible and prepared for further algebraic manipulations.