# integration constant question

by wumple
Tags: constant, integration
 P: 60 Hi, I thought that if you integrate with limits, you don't include a constant, but if you don't integrate with limits (indefinite), there is a constant. But my book gives the example (all functions are single variable functions, initially of x but then changed to s for the integration): $$f' = \frac{1}{2}(\phi'+\frac{\psi}{c})$$ Integrating: $$f(s) = \frac{1}{2}\phi(s) + \frac{1}{2c}\int_0^s\psi + A$$ What's going on here?
 Sci Advisor HW Helper P: 9,422 the first statement implies the second. I.e. if all you know about f is its derivative, then you can only know f up to an additive constant. try to get away from memorizing mindless rules like the (flawed) ones you stated. learn what the concepts mean.

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