AP Calculus BC : AP Calculus BC

Study concepts, example questions & explanations for AP Calculus BC

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Example Questions

Example Question #131 : Integral Applications

Give the arclength of the graph of the function  on the interval .

Possible Answers:

Correct answer:

Explanation:

The length of the curve of  on the interval  can be determined by evaluating the integral

.

, so 

The integral becomes

Use substitution - set . Then , and . The bounds of integration become  and , and the integral becomes

Example Question #1 : Average Values And Lengths Of Functions

What is the length of the curve  over the interval ?

Possible Answers:

Correct answer:

Explanation:

The general formula for finding the length of a curve  over an interval  is 

In this example, the arc length can be found by computing the integral

.

The derivative of  can be found using the power rule, , which leads to 

At this point, a substitution is useful.

Let 

.

We can also express the limits of integration in terms of  to simplify computation. When , and when .

Making these substitutions leads to 

.

Now use the power rule, which in general is , to evaluate the integral. 

Example Question #1 : Length Of Curve, Distance Traveled, Accumulated Change, Motion Of Curve

Find the total distance traveled by a particle along the curve  from  to .

Possible Answers:

Correct answer:

Explanation:

To find the required distance, we can use the arc length expression given by .

Taking the derivative of our function, we have . Plugging in our  values for our integral bounds, we have

.

As with most arc length integrals, this integral is too difficult (if not, outright impossible) to evaluate explicitly by hand. So we will just leave it this form, or evaluate it with some computer software.

Example Question #1 : Modeling By Solving Separable Differential Equations

Solve the separable differential equation

with the condition .

Possible Answers:

Correct answer:

Explanation:

To solve the separable differential equation, we must separate x and y, dx and dy respectively to opposite sides:

Integrating both sides, we get

The rules of integration used were

The constants of integration merged into one.

Now, we exponentiate both sides of the equation to solve for y, and use the properties of exponents to simplify:

To solve for C, we use our given condition:

Our final answer is

 

Example Question #1 : Parametric Form

Rewrite as a Cartesian equation:

Possible Answers:

Correct answer:

Explanation:

So 

 or 

We are restricting  to values on , so  is nonnegative; we choose 

.

Also,

So 

 or 

We are restricting  to values on , so  is nonpositive; we choose

or equivalently,

to make  nonpositive.

 

Then,

and 

Example Question #1 : Parametric, Polar, And Vector Functions

Rewrite as a Cartesian equation:

Possible Answers:

Correct answer:

Explanation:

, so

This makes the Cartesian equation

.

Example Question #1 : Parametric, Polar, And Vector Functions

If  and , what is  in terms of  (rectangular form)?

Possible Answers:

Correct answer:

Explanation:

Given  and  , we can find  in terms of  by isolating  in both equations:

 

Since both of these transformations equal , we can set them equal to each other:

Example Question #191 : Ap Calculus Bc

Given  and , what is the arc length between ?

Possible Answers:

Correct answer:

Explanation:

In order to find the arc length, we must use the arc length formula for parametric curves:

.

Given   and , we can use using the Power Rule

 for all , to derive 

 and 

.

Plugging these values and our boundary values for  into the arc length equation, we get:

Now, using the Power Rule for Integrals

 for all ,

we can determine that:

Example Question #4 : Parametric, Polar, And Vector Functions

Given  and , what is the length of the arc from ?

Possible Answers:

Correct answer:

Explanation:

In order to find the arc length, we must use the arc length formula for parametric curves:

.

Given  and , we can use using the Power Rule

for all  , to derive

 and

 .

Plugging these values and our boundary values for into the arc length equation, we get:

Now, using the Power Rule for Integrals

for all ,

we can determine that:

Example Question #151 : Parametric, Polar, And Vector

Find the length of the following parametric curve 

,   ,   .

Possible Answers:

Correct answer:

Explanation:

The length of a curve is found using the equation 

We use the product rule,

, when  and  are functions of ,

the trigonometric rule,

 and  

and exponential rule,

 to find  and 

In this case

,   

 

The length of this curve is

Using the identity 

Using the identity 

Using the trigonometric identity  where  is a constant and 

Using the exponential rule, 

Using the exponential rule, , gives us the final solution

 

 

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