Question

State the reciprocal of (a) 9 , (b) \(\frac{4}{3}\), (c) \(\frac{4 x}{3 y}\).

Short answer

Question: Find the reciprocals of the following numbers and expressions: (a) 9 (b) \(\frac{4}{3}\) (c) \(\frac{4x}{3y}\) Answer: (a) The reciprocal of 9 is \(\frac{1}{9}\). (b) The reciprocal of \(\frac{4}{3}\) is \(\frac{3}{4}\). (c) The reciprocal of \(\frac{4x}{3y}\) is \(\frac{3y}{4x}\).

Step-by-step solution

(a) Reciprocal of 9

To find the reciprocal of 9, think of 9 as a fraction: \(\frac{9}{1}\). Now, switch the numerator and the denominator: \(\frac{1}{9}\). The reciprocal of 9 is \(\frac{1}{9}\).

(b) Reciprocal of \(\frac{4}{3}\)

To find the reciprocal of \(\frac{4}{3}\), switch the numerator and the denominator: \(\frac{3}{4}\). The reciprocal of \(\frac{4}{3}\) is \(\frac{3}{4}\).

(c) Reciprocal of \(\frac{4x}{3y}\)

To find the reciprocal of \(\frac{4x}{3y}\), switch the numerator and the denominator: \(\frac{3y}{4x}\). The reciprocal of \(\frac{4x}{3y}\) is \(\frac{3y}{4x}\).

Key concepts

Fractions

Fractions are fundamental building blocks in mathematics. A fraction represents a part of a whole. It consists of a top number, known as the "numerator," and a bottom number called the "denominator." The line between them is often referred to as the fraction bar. This concept is crucial because fractions can express anything from simple portions like one-half (\(\frac{1}{2}\)) to more complex parts in various applications.Understanding fractions entails comprehending how these numbers work together to form a value that is less than or equal to one. The fraction \(\frac{4}{3}\), for example, signifies that four parts are considered over the three parts of the whole. Generally speaking, fractions can be proper (where the numerator is smaller than the denominator), improper (numerator is larger than the denominator), or mixed numbers, which combine whole numbers and fractions.

Numerator and Denominator

In a fraction, the numerator and the denominator play specific roles. The numerator is the number above the fraction bar, representing the "part" of something. The denominator is below the fraction bar, indicating the "whole" to which the part relates. When we look at a fraction like \(\frac{4}{3}\), the numerator is 4, and the denominator is 3.This division explains how many parts the whole is divided into, with the numerator showing how many of these parts are being considered. Understanding the difference between the numerator and denominator is essential. It is particularly important for operations like finding a reciprocal, where you swap the values of the numerator and the denominator. By flipping them, as done with finding \(\frac{3}{4}\) from \(\frac{4}{3}\), you effectively invert the relationship between parts and the whole.

Mathematical Operations

Mathematical operations such as addition, subtraction, multiplication, and division can all be applied to fractions. One of the unique operations linked with fractions is finding the reciprocal. The reciprocal of a fraction is achieved by swapping its numerator and denominator. This operation effectively "flips" the fraction.To find the reciprocal of a whole number like 9, first express it as a fraction: \(\frac{9}{1}\). Then, switching the numerator and the denominator gives us \(\frac{1}{9}\) as the reciprocal. This idea extends to more complex fractions such as \(\frac{4x}{3y}\), where the reciprocal becomes \(\frac{3y}{4x}\) by swapping the top and bottom terms.Understanding these operations, including creating reciprocals, enables more complex calculations, such as solving equations and simplifying expressions in algebra and calculus. Each operation has a specific role in manipulating and understanding the relationships between numbers.