Simplify The Expression Assuming That X And Y Are Nonnegativ

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Simplify the given expressions assuming that x and y are nonnegative real numbers. The tasks include simplifying algebraic expressions, working with radicals, performing operations like multiplication and division involving radicals, rewriting expressions using radical notation, and rationalizing denominators to achieve simplified forms with positive exponents.

Paper For Above instruction

Mathematical simplification is fundamental in algebra, especially when working with radicals and expressions involving variables. When the variables involved are nonnegative real numbers, simplifications often become more straightforward because the square roots and other radicals are well-defined, and negative values are excluded. This paper discusses various methods for simplifying expressions with radicals, performing operations with radicals, rewriting expressions in radical notation, and rationalizing denominators to produce simplified forms with only positive exponents.

1. Simplification of Algebraic Expressions with Nonnegative Variables

When simplifying algebraic expressions, the goal is to combine like terms, reduce radical expressions, and eliminate unnecessary complexity. For example, consider expressions such as √(x²) or √(y²). Because x and y are nonnegative, √(x²) simplifies directly to x, and √(y²) simplifies to y. Therefore, the expression √(x²) + √(y²) simplifies to x + y.

Similarly, expressions involving powers and roots such as x^m * x^n can be combined using exponent rules: x^{m + n}. If radicals are involved, rewriting roots in exponential form (e.g., √x = x^{1/2}) facilitates simpler manipulation.

2. Simplifying Expressions with Radicals

Simplifying radical expressions involves reducing the radical to its simplest form, factoring under the radical, and extracting perfect squares. For instance, √(12) can be simplified to 2√(3) because 12 = 4 3, and √4 = 2. For more complex expressions like √(x^4 y^2), the radical simplifies to x^2 y because all exponents are even or divisible by 2. The key is to factor the radicand into perfect squares and use the property that √(a b) = √a * √b.

3. Operations with Radicals

When performing addition or subtraction involving radicals, the radicals must be like terms; that is, the radicals must have the same radicand. For example, 3√(2) + 5√(2) simplifies to 8√(2). However, √(3) + √(2) cannot be combined unless approximated or converted to decimals.

Multiplication of radicals follows the property √a √b = √(a b). For example, √( 3 ) * √( 12 ) simplifies to √(36) = 6. Division involves the inverse and can be simplified similarly, provided the radicands are adjusted accordingly.

4. Rewriting Expressions with Radical Notation

Expressing algebraic expressions in radical notation often involves converting powers to roots for clarity or calculation convenience. For example, x^{1/3} is written as √(x)^, indicating the cube root of x. Rewriting expressions in radical notation simplifies the visualization and calculation of roots, especially for fractional exponents.

5. Rationalizing Denominators

One common form of simplification is rationalizing the denominator in a fraction with radical terms. For example, to rationalize 1 / √2, multiply numerator and denominator by √2, resulting in √2 / 2. If the denominator is a binomial such as a + √b, multiply numerator and denominator by its conjugate a - √b to eliminate radicals from the denominator. This process simplifies expressions and ensures that the denominator contains only rational numbers.

6. Examples of Rationalization

Suppose the expression is 1 / (3 + √5). Multiplying numerator and denominator by the conjugate 3 - √5, we obtain:

(1 * (3 - √5)) / ((3 + √5)(3 - √5)) = (3 - √5) / (9 - 5) = (3 - √5) / 4

This simplifies the original expression into a form with a rational denominator.

7. Expressing with Only Positive Exponents

In algebra, expressing all parts of an expression with positive exponents is often required for consistency and simplicity. For example, x^{-2} y^{3} is rewritten as y^{3} / x^{2} . This process involves applying the rule a^{-m} = 1 / a^{m} for negative exponents.

Conclusion

Simplifying algebraic and radical expressions under the assumption of nonnegative variables involves applying fundamental algebraic rules and properties of radicals. Key techniques include simplifying radicals via factorization, combining like radicals, performing operations with radicals while respecting their properties, rewriting expressions for clarity, and rationalizing denominators to produce cleaner, more manageable expressions. Mastery of these techniques enhances algebraic fluency and prepares students for more advanced mathematical work, including calculus and applied mathematics.

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