Calculus
Lesson
20 Antiderivatives
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is the
"Antiderivative" of
when
.
Find
:

What about adding a constant? If
and
, note that
they have the same derivative.
So if
, then
, where we
call
the
"constant of integration."
So, here is the proper way to solve for a function, given its derivative:

Always think: what would I have to differentiate to get
this function?
Two ways to think about it:

More exmples: 
Sometimes you may have to re-write the polynomial or trig function:

Finally, note that
,
thus far, could be anything. (Plot
which
is the antiderivative of
since
).
Pick an initial condition to solve . For instance, let's
say that we knew that
.
REALLY FINALLY, solve the differential equation:![]()