Question

Describe the following set in Roster form. The set of all letters of the word “Trigonometry.”

Answer 1

Hint: Recall the definitions of a set expressed in set-builder form and roster form. Think about a statement which will include all the letters of the word Trigonometry. Remember that mathematical statements can be English sentences also.

Complete step-by-step answer:
Set Builder form: In this form, we express the elements by mentioning their common property, e.g. if a set contains elements 1, 5 and 7 then the set builder form of the set is {x: (x-1)(x-5)(x-7)=0}
Roster form: In roster form, we list all the elements of the set, e.g. if a set contains elements 1,5 and 7 then in roster form we write the set as {1,5,7}.
From the above discussion, it is clear that the set containing all the elements of the word Trigonometry is {t,r, i,g,o,n,m,e,r,y}.

Note: [1] In a set repetition of elements is immaterial. Hence all the repeated letters of the word trigonometry have been written only once in the roster form. Hence two sets A and B are said to be equal if every element of set A is in set B and every element in set B is also in set A. [2] The sets {1,2,3,3,4,5,4} and {1,2,3,4,5} are equal as every element in the first set is also in the second set and every element in the second set is also in first.