# Calculus 2 : Indefinite Integrals

## Example Questions

### Example Question #1 : Indefinite Integrals

Find the indefinite integral of the following function:

Explanation:

To integrate this function, use u substitution. Make,

then substitute them into the equation to get

.

The integral of

then plug u back into the equation

.

The +C is essential because the integral is indefinite.

### Example Question #1 : Indefinite Integrals

Evaluate the given indefinite integral

.

Explanation:

To integrate this function, use u substitution. Make

then substitute them into the equation to get

.

The integral of

then plug u back into the equation

.

The +C is essential because the integral is indefinite.

### Example Question #3 : Indefinite Integrals

Evaluate the given indefinite integral

.

Explanation:

To integrate this function, use u substitution. Make

then substitute them into the equation to get

.

The integral of

so we have

The +C is essential because the integral is indefinite.

### Example Question #1 : Indefinite Integrals

Calculate the following indefinite integral.

Explanation:

To calculate the integral, we need to use integration by parts. The definition for integration by parts is

It is important here to select the correct u and dv terms from our orginal integral. We eventually want of the terms to "go away" when we take its derivate. We notice here that out of our two functions in our integral,  and , the derivate of x is 1, making is very simple to integrate eventually. Therefore,  will be our  term, and  will be our dv term. Note that the dv term is not just dx, but the function attached to it as well. If  was our  term, then  would be our dv term.

Now calculate the terms  and  needed to proceed with the integration by parts equation.

(you can to set integration constant c=0)

Now that we have the terms that we need, we can plug in these terms into the integration by parts formula above.

-

Note that although we still need to integrate one more time, this new integral only consists of one function which is simple to integrate, as opposed to the two functions we had before. Also note that the x term from the initial integral "went away", thus making the resulting integral easy to calculate.

Simplifying this term now becomes

.

### Example Question #5 : Indefinite Integrals

If

What is

?

Explanation:

Although the integral looks difficult, it can be majorly simplified. Remember this crucial trig identity.

Using this identity, the integral can now be simplified to

, which is very simple to integrate.

### Example Question #6 : Indefinite Integrals

Solve the following for .

Assume the integration constant  is zero.

Explanation:

In this problem we can try to get all the terms with  on one side and all the terms with  on the other.

Now we can integrate both sides using the definition of  and the power rule.

and

### Example Question #7 : Indefinite Integrals

Solve the following for .

Assume the integration constant

Explanation:

Move all expressions with  to one side and all  to the other.

Now integrate both sides using the power rule and the definition of natural log.

The power rule for integrals states,

and the definition of natural log is,

.

Applying these rules we are able to solve the problem.

### Example Question #8 : Indefinite Integrals

Evaluate the following integral.

Explanation:

We need to use the following identity:

Our integral now becomes

.

Notice inside the cosine becomes 4 because we already had a 2 in the original expression.

This can be split into two integrals

.

Which becomes

.

### Example Question #9 : Indefinite Integrals

Find the indefinite integral of .

None of the above

Explanation:

We can find the indefinite integral of   using the Power Rule for Integrals, which states that

for all  and with the arbitrary constant of integration .

Applying this rule to

### Example Question #10 : Indefinite Integrals

Find the indefinite integral of .