What happens if r = 1?

Every term equals the first term, so the sum is simply the first term multiplied by n.

Geometric Sequence Calculator

Calculate the nth term and the sum of the first n terms of a geometric sequence given the first term and common ratio.

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Formula

aₙ = a₁ × r^(n−1), Sₙ = a₁(1−rⁿ)/(1−r)

Trapezoid Area and Number Sequences Explained

The trapezoid area formula and the arithmetic vs. geometric sequence formulas, worked through with real examples.

Arithmetic Sequence Calculator

Find the nth term and sum of an arithmetic sequence.

Percentage Calculator

Find what percentage one number is of another, or calculate percentage change.

Percentage Change Calculator

Calculate the percentage increase or decrease between two values.

Quadratic Equation Solver

Solve ax² + bx + c = 0 for real roots using the quadratic formula.

Average (Mean) Calculator

Calculate the average of up to 10 numbers.

Standard Deviation Calculator

Calculate the population standard deviation of up to 5 numbers.