Meaning & use
variable
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Meanings
nouncountablemathematics
A symbol representing a value that can change or is not yet known.
Grammar: Countable in mathematics; often named x, y, or another letter.
Patterns
- variable in an equation
- solve for a variable
- independent variable
In y = 2x + 1, x is the variable.
Solve the equation for the unknown variable.
Changing one variable changes the result of the formula.
nouncountablespecialist
A factor or quantity that can take different values in an experiment or investigation.
Grammar: Common in science and statistics; researchers control some variables and measure others.
Patterns
- control a variable
- dependent variable
- variables in a study
Temperature was the main variable in the experiment.
The study measured sleep as a variable affecting memory.
Researchers tried to keep every other variable constant.
Word forms
| plural | variables |
|---|
Common combinations
- independent variable
- Time was the independent variable in the growth experiment.
- dependent variable
- Test scores were the dependent variable measured at the end.
- control for a variable
- The team controlled for age when comparing the two groups.
- key variables
- Cost and distance are key variables when choosing a school.
Synonyms and how they differ
- unknown
- In equations, a value to be found; variable is broader and can vary.
- factor
- An element that affects a result; not always represented by a symbol.
- parameter
- In many models a parameter is fixed, unlike a variable, though usage varies by field.
Opposites
Word family
- vary verb
- To change or be different.
- varied adjective
- Showing different types or changes.
- various adjective
- Several different kinds or examples.
- variation noun
- A difference or change in amount, form, or level.
- variability noun
- The degree to which something tends to change.
Commonly confused: variable or vary? variable or various?
variable vs vary
Vary is the verb meaning change; variable is often a noun for the changing value.
variable vs various
Various means several different; variable means able to change or the changing item itself.
Practice
In y = 3x + 2, x is a ___ whose value can change.
Choose one answer.
In this formula x can take many values, so it is a variable. A constant stays fixed, an equation is the whole statement, and number is too broad for the specific role x plays.
Make it your own
Write a sentence using “variable”, then check it and compare it with the examples above.