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Formulas/maths/Sequences and Series

Sequences and Series

Common Difference of an AP
Gives the constant difference between any term and its predecessor in an arithmetic progression.
nth Term of an AP
Gives the nth term of an arithmetic progression with first term a and common difference d.
nth Term from the End of an AP
Gives the nth term from the end of a finite arithmetic progression having last term l.
Sum of First n Terms of an AP
Gives the sum of the first n terms of an arithmetic progression given the common difference or the last term.
nth Term from Sum of n Terms
Gives the nth term of any sequence from the formula for the sum of its first n terms.
Condition for Three Terms in AP
Gives the condition for three real numbers a, b, and c to form an arithmetic progression.
Arithmetic Mean of Two Numbers
Gives the arithmetic mean of two numbers a and b.
Common Difference for n Inserted AMs
Gives the common difference when inserting n arithmetic means between a and b.
nth Term of a GP
Gives the nth term of a geometric progression with first term a and common ratio r.
Sum of First n Terms of a GP
Gives the sum of the first n terms of a geometric progression.
Sum of an Infinite GP
Gives the sum to infinity of an infinite geometric progression when the absolute common ratio is less than 1.
Condition for Three Terms in GP
Gives the condition for three non-zero numbers a, b, and c to form a geometric progression.
Geometric Mean of Two Positive Numbers
Gives the geometric mean of two positive real numbers a and b.
Common Ratio for n Inserted GMs
Gives the common ratio when inserting n geometric means between positive numbers a and b.
Sum of First n Natural Numbers
Gives the sum of the first n positive integers.
Sum of Squares of First n Natural Numbers
Gives the sum of the squares of the first n positive integers.
Sum of Cubes of First n Natural Numbers
Gives the sum of the cubes of the first n positive integers.