Podcast
Questions and Answers
What is the condition for two variables to vary directly in direct variation problems?
What is the condition for two variables to vary directly in direct variation problems?
- a / b = c
- ab - c
- ab + c
- ab = c (correct)
In direct variation, what do the terms 'k' and 'm' represent respectively?
In direct variation, what do the terms 'k' and 'm' represent respectively?
- Variable and rate of change
- Constant and variable
- Rate of increase and constant (correct)
- Rate of decrease and constant
In the equation y = 2x + 5, what does the coefficient '2' represent?
In the equation y = 2x + 5, what does the coefficient '2' represent?
- Dependent variable
- Exponential growth rate
- Constant 'k'
- Rate of increase (correct)
How is the rate of increase defined in linear equations in the context of direct variation?
How is the rate of increase defined in linear equations in the context of direct variation?
Which type of functions involve direct variation in the study of exponential growth and decay?
Which type of functions involve direct variation in the study of exponential growth and decay?
Which part of the linear equation represents how much the dependent variable increases for each unit increase in the independent variable?
Which part of the linear equation represents how much the dependent variable increases for each unit increase in the independent variable?
What happens when two variables vary directly according to direct variation theory if 'a' decreases and 'b' increases?
What happens when two variables vary directly according to direct variation theory if 'a' decreases and 'b' increases?
'y = kx' and 'y = mx + b' are often used to find the value of the constant 'c' in direct variation problems. What does 'b' represent in these equations?
'y = kx' and 'y = mx + b' are often used to find the value of the constant 'c' in direct variation problems. What does 'b' represent in these equations?
Study Notes
Direct Variation in Math
Direct variation is a mathematical term that describes how two variables change together. It can be defined as:
If one variable changes by a factor of
aand the other changes by a factor ofb, then they vary directly ifab = c.
In direct variation problems, you can often find the value of the constant c by using either of the following expressions:
y = kx
or
y = mx + b
The terms k and m represent the rate of increase. In linear equations, this rate is given by the coefficient of the independent variable (the variable that shows up with an exponent of 1), which is m in the second equation. This means that each unit increase in the independent variable causes an increase of m units in the dependent variable.
For example, let's consider the equation y = 2x + 5. Here, m = 2 represents the rate of increase of the dependent variable y with respect to the independent variable x. In this case, each time x increases by 1 unit, y will also increase by 2 units.
Direct variation is used in many areas of mathematics and science because it helps to understand how different quantities are related. For instance, it plays a crucial role in the study of exponential growth and decay, where e^t, e^-t, or e^(at) are involved. By understanding the properties of these functions, we can analyze various phenomena in physics, chemistry, economics, and more.
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Description
Learn about direct variation in mathematics, which describes how two variables change together using a constant factor. Explore linear equations and the rate of increase represented by the coefficient of the independent variable. Discover how direct variation is applied in various fields of mathematics and science.
