Antiderivative
Indefinite Integral
Checking
Indefinite Integral Formulas


                  Indefinite Integrals
One interpretation of the derivative of a function is that the drivative gives you the slope
of the graph of the function. Given a function, you can find the slope at a specific point
of the graph of the function by finding the value of the derivative of the function at that
specific point.
For example, if the function is

then to find the slope of the graph of the function at the point , you find the
derivative of the function

and substitute .
At that point the slope of the graph is



The problem going in the opposite direction is to find the function itself when you
are first given the derivative of the function.
For this example, the problem would be to find when you are given that
.
The solution of this problem brings in the integral calculus.
The monomial   is simple enough so it is not so hard to determine that   
works for a solution.

So is a solution to the problem.
But
, , and
all work too, as you can verify by taking their drivative.
Each of these functions is called an antiderivative of .
In fact, any combination of the form    , where C is a constant, works.

The general form is called the indefinite integral of .
The notation is

is called the constant of integration.
In general,

where
.


                  Checking an Indefinite Integral


Is the integral correct ?
You can check by differentiating the right side of the equation. If you get the integrand
as the result, then the integral is correct.



The integral is correct !

See Examples 2 - 3, pages 315 - 316.


                  Indefinite Integral Formulas
Here are some indefinite integral formulas from Table 4.1, page 315, of the text
and their proofs.

Formula 1]
                
because


The restriction is needed because when , the denominator become .
Later, the formula will be extended to the case where .
The extension will involve a transcendental function, the natural logarithm of .


Formula 2]
                   
because




Formula 6]
                
because





By the quotient rule for derivatives




Some examples of using the above formulas are



and





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