AP Calculus AB : Functions, Graphs, and Limits

Study concepts, example questions & explanations for AP Calculus AB

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Example Questions

Example Question #331 : Ap Calculus Ab

Evaluate:

 .

Possible Answers:

Correct answer:

Explanation:

For this problem we need to use the U Substitution Method.

Using the U-du Rule you can set  and .

Because we only have a dx in our problem we need to solve for dx, thus 

.

When  and when

Therefore your new equation will be:

 

.

Plugging in our interval we get,

 

Example Question #125 : Asymptotic And Unbounded Behavior

Evaluate:

Possible Answers:

 

Correct answer:

 

Explanation:

The first step is to find the antiderivative, recalling that:

.  

 

For this integral:

where the intergral would be evaluated from  to  (the absolute value bar is not necessary, since both limits of integration are greater than zero):

Example Question #126 : Asymptotic And Unbounded Behavior

Evaluate the following indefinite integral:

Possible Answers:

Correct answer:

Explanation:

Use substitution, where  and .  Thus, the integral can be rewritten as:

.

Substitution of  back into this expression gives the final answer:

Note that since this is an indefinite integral, the addition of a constant term (C) is required.

Example Question #131 : Functions, Graphs, And Limits

Evaluate the limit:

 

Possible Answers:

The limit does not exist

Correct answer:

Explanation:

When evaluating the limit as x approaches infinity, we must compare the magnitude of the functions. The exponential function in the numerator grows faster than the polynomial function (and any polynomial, for that matter) in the denominator, so the numerator dominates and the limit equals 

Example Question #1 : Calculating Limits Using Algebra

Calculate 

Possible Answers:

5

10

The limit does not exist

0

Correct answer:

10

Explanation:

First we notice that substituting 5 in for x will give us a 0 in the denominator.

So we simplify the equation by noticing the numerator is the difference of two squares.

Now we can substitute 5 in for x, and we arrive at our answer of 10.

Example Question #2 : Calculating Limits Using Algebra

Evaluate the following limit:

Possible Answers:

Correct answer:

Explanation:

Factor x-4 out of the numerator and simplify:

 

Evaluate the limit for x=4:

Although there is a discontinuity at x=4, the limit at x=4 is 10 because the function approaches ten from the left and right side.

Example Question #3 : Calculating Limits Using Algebra

Evaluate the following limit:

Possible Answers:

Correct answer:

Explanation:

Factor the numerator and simplify the expression.

Evaluate the function at x=2.

There is a discontinuity at x=2, but since it the limit as x approaches 2 from the right is equal to the limit as x approaches 2 from the left, the limit exists.

 

 

Example Question #4 : Calculating Limits Using Algebra

Evaluate the following limit:

Possible Answers:

does not exist

Correct answer:

Explanation:

Factor the numerator to evaluate the limit:

Evaluate the limit:

There is a discontinuity at x=0 but the limit is equal to 8 because the limit from the right is equal to the limit from the left.

 

Example Question #5 : Calculating Limits Using Algebra

Evaluate the following limit:

Possible Answers:

Correct answer:

Explanation:

As x approaches infinity, the x values that are raised to the highest power dominate the function and all other values become negligible. In this limit, x3 has the highest order in the numerator and 5x2 has the highest power of all the values in the denominator. We can simplify the limit to the following:

 

After factoring out x2 it is easy to see that the limit diverges to infinity.

 

 

Example Question #1 : Limits Of Functions (Including One Sided Limits)

Possible Answers:

Undefined.

Correct answer:

Explanation:

The first step to evaluating limits is always attempt to direct substitute the value into the function.  In this case, that is all you need to do. 

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