Calculus 3 : Calculus 3

Study concepts, example questions & explanations for Calculus 3

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Example Questions

Example Question #1651 : Calculus 3

Find the gradient vector for the following function:

Possible Answers:

Correct answer:

Explanation:

The gradient vector of the function is given by

To find the given partial derivative of the function, we must treat the other variable(s) as constants.

The partial derivatives are

Example Question #92 : Gradient Vector, Tangent Planes, And Normal Lines

Find the gradient vector for the following function:

Possible Answers:

Correct answer:

Explanation:

The gradient vector of the function is given by

To find the given partial derivative of the function, we must treat the other variable(s) as constants.

The partial derivatives are

Example Question #1652 : Calculus 3

Write the equation of the tangent plane to the following function at :

Possible Answers:

Correct answer:

Explanation:

The equation of the tangent plane is given by

So, we must find the partial derivatives for the function evaluated at the point given. To find the given partial derivative of the function, we must treat the other variable(s) as constants.

The partial derivatives are

The partial derivatives evaluated at the given point

Plugging our known information into the equation above, we get

which simplifies to

Example Question #94 : Gradient Vector, Tangent Planes, And Normal Lines

Find the function with the gradient:

 that satisfies the condition 

 

Possible Answers:

 

Correct answer:

Explanation:

One easy solution is to just compute the gradients of each of the multiple choices for this problem and then apply the given condition . If your exam is not multiple choice, you will have to use a more insightful approach. Compare the given gradient to the general definition of a gradient: 

 

                                                     (1)

Since we obtain the gradient by computing the partial derivatives of each independent variable, we can obtain the function by integrating each component and then combining the results to write a single expression for 

 

 

 

Looking at the results, note that each we obtained may include either some of the terms or all of the terms of the functions actual function. In this case, integrating the  component gave back all the terms of

So our function will have the form:

 

Apply the condition 

Therefore the function we were looking for has the form: 

 

 

Example Question #3 : Line Integrals

Compute  for 

Possible Answers:



Correct answer:

Explanation:

In order to find the divergence, we need to remember the formula.

Divergence Formula:

, where , and  correspond to the components of a given vector field .

 

Now lets apply this to our situation.

 

Example Question #3 : Line Integrals

Compute  for 

Possible Answers:

Correct answer:

Explanation:

In order to find the divergence, we need to remember the formula.

Divergence Formula:

, where , and  correspond to the components of a given vector field .

 

Now lets apply this to our situation.

 

Example Question #4 : Line Integrals

Compute  for 

Possible Answers:

Correct answer:

Explanation:

In order to find the divergence, we need to remember the formula.

Divergence Formula:

, where , and  correspond to the components of a given vector field .

 

Now lets apply this to our situation.

 

Example Question #4 : Line Integrals

Find , where 

Possible Answers:

Correct answer:

Explanation:

In order to find the divergence, we need to remember the formula.

Divergence Formula:

, where , and  correspond to the components of a given vector field .

 

Now lets apply this to our situation.

 

Example Question #1 : Divergence

Compute , where 

Possible Answers:

Correct answer:

Explanation:

All we need to do is calculate the partial derivatives and add them together.

Example Question #1 : Divergence

Given the vector field

find the divergence of the vector field:

.

Possible Answers:

Correct answer:

Explanation:

Given a vector field 

we find its divergence by taking the dot product with the gradient operator:

We know that , so we have 

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