Expand menu menu_open Minimize Go to startpage home Home History history History expand_more
{{ item.displayTitle }}
navigate_next
No history yet!
Progress & Statistics equalizer Progress expand_more
Student
navigate_next
Teacher
navigate_next
{{ filterOption.label }}
{{ item.displayTitle }}
{{ item.subject.displayTitle }}
arrow_forward
No results
{{ searchError }}
search
menu
{{ courseTrack.displayTitle }} {{ printedBook.courseTrack.name }} {{ printedBook.name }}
{{ statistics.percent }}% Sign in to view progress
search Use offline Tools apps
Digital tools Graphing calculator Geometry 3D Graphing calculator Geogebra Classic Mathleaks Calculator Codewindow
Course & Book Compare textbook Studymode Stop studymode Print course
Tutorials Video tutorials Formulary

Video tutorials

How Mathleaks works

Mathleaks Courses

How Mathleaks works

play_circle_outline
Study with a textbook

Mathleaks Courses

How to connect a textbook

play_circle_outline

Mathleaks Courses

Find textbook solutions in the app

play_circle_outline
Tools for students & teachers

Mathleaks Courses

Share statistics with a teacher

play_circle_outline

Mathleaks Courses

How to create and administrate classes

play_circle_outline

Mathleaks Courses

How to print out course materials

play_circle_outline

Formulary

Formulary for text courses looks_one

Course 1

looks_two

Course 2

looks_3

Course 3

looks_4

Course 4

looks_5

Course 5

Login account_circle menu_open

Index

Concept

Index

Sometimes instead of using different variables for different values, an index is used with the same variable. To distinguish between values, the index is written as a subscript to the term.

Index

Indices can be used to specify multiple solutions of an equation or unknown terms of a sequence. a1, a2, a3,,an a_1, \ a_2, \ a_3, \ldots, \, a_n Since there is a finite number of letters, writing these unknown terms in this way, rather than a,a, b,b, c,,c,\ldots, allows more flexibility in expressing the sequence.

{{ 'mldesktop-placeholder-grade-tab' | message }}
{{ 'mldesktop-placeholder-grade' | message }} {{ article.displayTitle }}!
{{ grade.displayTitle }}
{{ exercise.headTitle }}
{{ 'ml-tooltip-premium-exercise' | message }}
{{ 'ml-tooltip-programming-exercise' | message }} {{ 'course' | message }} {{ exercise.course }}
Test
{{ 'ml-heading-exercise' | message }} {{ focusmode.exercise.exerciseName }}
{{ 'ml-btn-previous-exercise' | message }} arrow_back {{ 'ml-btn-next-exercise' | message }} arrow_forward