# Definition--Calculus Topics--Delta y

Calculus

## Definition

Delta y (Δy) represents the change in the y-coordinate (or function value) between two points on a function. It is calculated as the difference between the final y-value and the initial y-value: Δy = y₂ - y₁.

## Description

Delta y is a crucial concept in calculus, particularly in understanding rates of change and the behavior of functions. It's fundamental to the definition of average rate of change and plays a key role in the development of derivatives. In real-world applications, Delta y is used to model changes in dependent variables across various fields, such as physics (for changes in velocity), economics (for changes in profit), and biology (for population growth).

In mathematics education, Delta y helps students visualize and quantify how functions change. It's essential for developing intuition about function behavior, slopes, and rates of change. When paired with Delta x, it provides a concrete way to understand average rate of change and lays the groundwork for the concept of instantaneous rate of change (derivatives).

Teacher's Script: "Let's consider a company's sales over two months. In January, they sold 1000 units (y₁), and in February, they sold 1200 units (y₂). The Delta y here would be 1200 - 1000 = 200 units. This tells us how much the sales increased. Now, if we divide this Delta y by the time interval (Delta x, which is 1 month), what do we get? That's right, the average rate of change in sales per month! Can you think of other scenarios where calculating Delta y would be useful?"

For a complete collection of terms related to Calculus click on this link: Calculus Vocabulary Collection.

Common Core Standards CCSS.MATH.CONTENT.HSF.IF.C.7, CCSS.MATH.CONTENT.HSF.BF.A.1.C 11 - 12 Algebra     • Advanced Topics in Algebra         • Calculus Vocabulary 2023 calculus concepts, limits, derivatives, integrals, composite functions