Question

Circle the irrational numbers.
a) π
b) 5/3
c) √4
d) -0.25

Answer 1

Circle π (pi) as it is the only irrational number in the list, identifiable by its infinite, non-repeating decimal expansion.

Step-by-step explanation:

An irrational number is a number that cannot be expressed as a simple fraction - that is, as a ratio of integers. Its decimal form does not end and does not form a repeating pattern. With that in mind, let's analyze the numbers provided:

1. π (pi): π is the ratio of the circumference of a circle to its diameter. While it is often approximated as 3.14, this is an example of a number that is irrational because its decimals extend infinitely without repeating.
2. 5/3: This is a simple fraction and therefore it is a rational number.
3. √4 (the square root of 4): This is equal to 2, which is an integer and therefore a rational number.
4. -0.25: This is a decimal that terminates and can also be expressed as the fraction -1/4, making it a rational number.

Therefore, the only irrational number in the list is π (pi).