AP Calculus AB : AP Calculus AB

Study concepts, example questions & explanations for AP Calculus AB

varsity tutors app store varsity tutors android store

Example Questions

Example Question #2 : How To Find Maximum Values

What is the local maximum of between and ?

Possible Answers:

There is no maximum between these two points.

Correct answer:

Explanation:

To find the maximum, we must find where the graph shifts from increasing to decreasing. To find out the rate at which the graph shifts from increasing to decreasing, we look at the second derivative and see when the value changes from positive to negative.

That is to say, we will look at the second derivative and see where (if at all) the graph crosses the x-axis and is moving from a positive y-value to a negative y-value.

Now we must find the second derivative. Unfortunately, the derivatives of trig functions must be memorized. The first derivative is:

.

To find the second derivative, we take the derivative of our result.

.

Therefore, the second derivative will be .

Does our new equation cross the x-axis and move from positive to negative between and ? Yes. It does once, when . Therefore, our local maximum shall be when . Plug that value back into our first equation to find that the maximum will be at the point .

Example Question #1 : How To Find Maximum Values

Find the x coordinate of the maximum of  over the interval .

Possible Answers:

-2

0

2

6

5

Correct answer:

2

Explanation:

First find the derivative, which is:

 

Set that equal to zero to get your critical points:

You also have to take into account -1 and 2 as critical points since those are your endpoints. Evaluate each of these critical points in the original function:

The greatest is your maximum. The x coordinate is 2.

Example Question #1 : How To Find Maximum Values

Find the value at which the function  f(x)=x^3-3x^2+3 reaches its local maximum.

Possible Answers:

Correct answer:

Explanation:

To find the maximum, we need to find the critical points. To do that, we need to take the derivatie of the function. f'(x)=3x^2-6x=0

And we can see that  and  are critical points for this function.

An easy way to see which is the maximum and which is the minimum is to plug in the values of the critical points into the original equation.

f(0)=3 and f(2)=-1

Therefore, the maximum value is 3, and the value at which the function reaches the maximum is 0.

Example Question #2 : Calculus I — Derivatives

Consider the function 

Find the minimum of the function on the interval .

Possible Answers:

Correct answer:

Explanation:

To find potential minima of the function, take the first derivative of  using the power rule.

Set the derivative to 0:

We solve for  to obtain  and then plug in 0.5 into the original function to obtain the answer of

We can double check that  is indeed a minimum by using the second derivative test

which means the function is concave up, so that the point we found is a minimum.

Example Question #71 : Integrals

Find the x coordinate of the minimum of  on the interval 

Possible Answers:

Correct answer:

Explanation:

First, find the derivative, which is:

 

Set that equal to 0 to find your critical points:

Evaluate f at each critical point and endpoint over [-2, 2]:

The least of those numbers is the minimum. Because f(-2)=-32, that is the minimum.

Example Question #1 : Identifying Absolute And Local Extrema

What is the local minimum of  when ?

Possible Answers:

The y-value is constant throughout that range.

There is no local minimum in that range.

Correct answer:

Explanation:

To find the maximum, we need to look at the first derivative. 

To find the first derivative, we can use the power rule. To do that, we lower the exponent on the variables by one and multiply by the original exponent.

We're going to treat  as  since anything to the zero power is one.

Notice that  since anything times zero is zero.

When looking at the first derivative, remember that if the output of this equation is positive, the original function is increasing. If the derivative is negative, then the function is decreasing.

Because we want the MINIMUM, we want to see where the derivative changes from negative to positive.

Notice that  has a root when . In fact, it changes from negative to positive at that particular point. This is the local minimum in the interval .

Example Question #6 : Techniques Of Antidifferentiation

Integrate, 

Possible Answers:

 

Correct answer:

 

Explanation:

Integrate

 

1) Apply the sum rule for integration, 

 

2) Integrate each individual term and include a constant of integration,  

 

Further Discussion

Since indefinite integration is essentially a reverse process of differentiation, check your result by computing its' derivative. 

This is the same function we integrated, which confirms our result. Also, because the derivative of a constant is always zero, we must include "C" in our result since any constant added to any function will produce the same derivative. 

 

 

 

Example Question #2 : Antiderivatives Following Directly From Derivatives Of Basic Functions

Possible Answers:

Correct answer:

Explanation:

Example Question #2 : Antiderivatives Following Directly From Derivatives Of Basic Functions

Possible Answers:

Correct answer:

Explanation:

Example Question #3 : Antiderivatives Following Directly From Derivatives Of Basic Functions

Possible Answers:

Correct answer:

Explanation:

Learning Tools by Varsity Tutors