Square
Maths
How to calculate arithmetic sequence sum
This tool calculates arithmetic sequence sum from First term, Common difference, Number of terms (integer ≥ 1). Enter each quantity in its labelled field, then use the formula below to check the calculation.
Formula
n ÷ 2 × (2a + (n − 1)d)
Worked example
- First term
- 2
- Common difference
- 3
- Number of terms (integer ≥ 1)
- 10
Applying the formula to these values gives 155 .
What should I check?
Calculate powers, roots, logarithms, ratios, slopes and trigonometric functions. Trigonometric angles are entered in degrees.
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