Sure, if you have some reference point for integration.
When you integrate an equation you get what is known as a constant of integration. That's a constant factor in the integrated equation that pops out of the integration process (e.g. if K is a constant its derivative is zero, consequently integral of zero is some constant K).
Consequently, some point has to be available to specify which equation out of the family of equations is the integral.
Look at it this way, if I have a line (y=mx+b) the differential of that line (dy/dx) is m (the slope?-lines have constant tangents). Now if I only have the slope (tangent) and integrate to get the line (e.g. ∫dy/dx dx =mx+K where K is come constant) I don't get the line I started with unless I have some reference for K. IOW I need to know some value of x at a particular y to determine that value of K that specifies the line in question (y=mx+b) where K=b.
The same thing exists for curves with changing tangents (slopes). Say I have a continuous Integra table* expression (df/dx) and some reference point (@ x=c, F(c )=M) then ∫df/dx dx =F(x)+K, the K=M-F(c )
____________________________________________________________________
As for the second question, that is effectively what Newton did with that falling apple. He observed that the velocity increased with its position over time and that velocity was the rate of change (derivative) of position. Through application of the calculus he was able to determine equations that would specify the position and the velocity at any point after the initial condition (@t=0 x=0).
Rap c∫

/