A speedometer tells you how fast you are going right now; the odometer tells you how far you have gone — integration is the mathematical odometer. In plain words, the indefinite integral rebuilds the original function from its slope: reverse the power rule by raising the exponent by one, dividing by the new exponent, and never forgetting +C. The integral of 3x² is x³ + C, because differentiating x³ gives back 3x². That +C stands for every constant the derivative erased — the slope alone cannot tell you the curve's height. Calculus students checking homework, physics majors recovering position from velocity, and economists rebuilding total cost from marginal cost all integrate. It is differentiation's undo button, with one free constant attached.

This calculator applies the reverse power rule. Type the exponent n into the Variable A box, say 2, and the coefficient into the Variable B box, say 3 for 3x². Read the Result box for the new coefficient — the old one divided by n+1: 1, giving x³. Then write +C after your answer, because the constant of integration is required, not decoration.

With the pre-filled defaults — Variable A 10, Variable B 5 — the Indefinite Integral Calculator returns Result 50.0000. Change any input and those results update instantly, so you can see exactly how each number you enter moves the answer.