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Lesson 8: Dependent and independent variables

# Dependent & independent variables

We introduce independent and dependent variables: how to identify the independent/dependent variable in a given setting, and how we write equations with the dependent variable by itself. Created by Sal Khan.

## Want to join the conversation?

• This is confusing
• It depends whether a variable is dependent or independent. In the video, he presents two scenarios:

scenario 1: you want to buy a certain number of apples
scenario 2: you have a limited budget.

In the first scenario, the number of apples (a) is the independent variable, but in the second one it's the total cost (c) since you decide how many apples or how much your budget is, the dependent variable depends on your decision of the independent variable.

Here's another analogy, a dependent variable is like a passenger in a car, and an independent variable is like the driver. The driver (the independent variable) determines the car's direction and speed, while the passenger (the dependent variable) goes along for the ride. In the same way, the value of the dependent variable depends on the value of the independent variable.
• I love apple
• how did get the apples
• Can someone tell me simply what an independent and dependent variables are and how they are different?
• independent variables are called by other names such as input, domain, etc. and dependent variables are called by output, range, etc. So you have to start with something to put into an equation (independent) to be able to calculate something (output). When we are thinking more abstract, we generally use x for input and y for output.
In Math and Science, you get equations that could shift inputs and outputs as needed. If you have A=bh, you could be given b and h as inputs to calculate A, or we could be given A and h to find b, so we would have to use b=A/h. Same thing would happen with h. We will often see the dependent variable isolated on one side by itself, but not always.
• are you a person
• Um, i guess
• why did we have to bring the alphabet into math?!?!
• wait, if the independent and dependent variables are interchangeable, how do we know which to label as which (idk if that made sense)?
• The dependent and independent variables change according to how you make the equation. Generally, dependent variables stay alone on one side of the equation, while the independent ones are in an operation(sum, subtraction, multiplication, division and so on).

Using the video example:

c = 2a --> c is dependent and a is independent(because it is multiplied by 2)

a = c/2 --> a is dependent and c is independent(because it is divided by 2)
(1 vote)
• Apples are now 2\$?