Density of Numbers Math Example 1
Follow the full solution, then compare it with the other examples linked below.
Example 1
mediumFind three rational numbers strictly between and .
Solution
- 1 Method 1 (mediant / averaging): Average of and : . First number: .
- 2 Average of and : . Second number: .
- 3 Average of and : . Third number: .
- 4 Check order: . β
Answer
Three rationals between and : , , .
The rationals are dense: between any two distinct rationals there are infinitely many more. Repeated averaging is a simple constructive method. This property β density β distinguishes rationals and reals from integers.
About Density of Numbers
The property that between any two distinct real numbers, there are infinitely many other real numbersβno two are 'adjacent'.
Learn more about Density of Numbers βMore Density of Numbers Examples
Example 2 hard
Show that there is an irrational number between [formula] and [formula], and find one explicitly.
Example 3 easyFind a rational number between [formula] and [formula] by averaging, and another by finding a decima
Example 4 mediumAre there integers between [formula] and [formula]? Are there rationals? Explain what this says abou