Radical

Definition

A radical is the square root symbol, $\sqrt{}$, which is used to represent the positive square root of a number or expression. Radicals are a fundamental concept in algebra, particularly in the context of solving quadratic equations using the square root property.

5 Must Know Facts For Your Next Test

1. Radicals are used to represent the positive square root of a number or expression.
2. Radicals are essential in solving quadratic equations using the square root property.
3. The square root property states that if $x^2 = a$, then $x = \pm \sqrt{a}$.
4. Radicals can be simplified by removing perfect squares from the radicand (the expression inside the radical).
5. Radicals can be combined using the laws of exponents, such as $\sqrt{a} \cdot \sqrt{b} = \sqrt{ab}$.

Review Questions

• Explain how the square root property is used to solve quadratic equations.
  • The square root property is used to solve quadratic equations of the form $x^2 = a$, where $a$ is a constant. By applying the square root property, we can conclude that $x = \pm \sqrt{a}$. This means that there are two solutions to the equation, one positive and one negative. The square root property is a key step in solving certain types of quadratic equations using the method of solving by taking the square root.
• Describe the process of simplifying radicals.
  • To simplify a radical expression, we need to remove any perfect squares from the radicand (the expression inside the radical). This is done by factoring the radicand and identifying the largest perfect square factor. We then write the radical as the product of the square root of the perfect square factor and the square root of the remaining factor. For example, $\sqrt{75}$ can be simplified to $5\sqrt{3}$ because $75 = 25 \cdot 3$, and $\sqrt{25} = 5$.
• Analyze the relationship between radicals and the laws of exponents.
  • Radicals are closely related to the laws of exponents. For example, the law $\sqrt{a} \cdot \sqrt{b} = \sqrt{ab}$ demonstrates how radicals can be combined using the laws of exponents. Similarly, the law $\sqrt{a^n} = a^{n/2}$ shows how radicals can be rewritten using fractional exponents. Understanding these connections between radicals and exponents is crucial for manipulating and simplifying radical expressions, which is an important skill in solving quadratic equations using the square root property.

Related terms

Square Root:

The square root of a number is the value that, when multiplied by itself, gives the original number. The square root symbol, $\sqrt{}$, is used to represent the square root of an expression.

Quadratic Equation:

A quadratic equation is an equation of the form $ax^2 + bx + c = 0$, where $a$, $b$, and $c$ are real numbers and $a \neq 0$.

Square Root Property:

The square root property states that if $x^2 = a$, then $x = \pm \sqrt{a}$. This property is used to solve certain types of quadratic equations.