Calculus 3 : Calculus 3

Study concepts, example questions & explanations for Calculus 3

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Example Questions

Example Question #66 : Equations Of Lines And Planes

Find the equation of the plane from the points on the plane  and 

Note: Use the point  when forming the equation of the plane

Possible Answers:

Correct answer:

Explanation:

First, we need to form two vectors on the plane to get the normal vector to the plane. This is done from the following operation:

We then take the cross product of these vectors, which gets us the normal vector

Plugging the point  and the normal vector into the equation of the plane, we get

Simplifying, we get

 

 

Example Question #67 : Equations Of Lines And Planes

Find the equation of the plane tangent to the surface  at the point where  and 

 

Possible Answers:

Correct answer:

Explanation:

Find the equation of the plane tangent to the surface  at the point where  and 

 

                                                                                 (1) 

The equation of the plane tangent to the surface defined by  is given by the formula: 

              (2)

 

In Equation (2)  and  are the partial derivatives of  with respect to  and , respectively. For this particular problem we have  

 

Let's fill in Equation (2) term-by-term: 

 

Compute the partial derivative and then evaluate both at  

- Partial with respect to x 

  

- Partial with respect to 

 

 

Now fill in Equation (2) and simplify to get the equation of the tangent plane: 

 

Therefore the equation of the tangent plane to the surface  at the point  is simply 

 

 

 

 

Example Question #61 : Equations Of Lines And Planes

Find the equation of the plane that contains the point  and the normal vector 

Possible Answers:

 

Correct answer:

 

Explanation:

To find the equation of the plane, we use the formula , where the point given is  and the normal vector . Plugging in what we were given in the problem statement, we get . Manipulating the equation through algebra to isolate the variables, we get  .

Example Question #1 : Parametric Curves

Find the length of the parametric curve described by

from  to .

 

Possible Answers:

None of the other answers

Correct answer:

Explanation:

There are several ways to solve this problem, but the most effective would be to notice that we can derive the following-

Hence

Therefore our curve is a circle of radius , and it's circumfrence is . But we are only interested in half that circumfrence ( is from  to , not .), so our answer is .

 

Alternatively, we could've found the length using the formula

.

Example Question #2 : Parametric Curves

Find the coordinates of the curve function


when .

Possible Answers:

Correct answer:

Explanation:

To find the coordinates, we set  into the curve function.

We get

and thus

Example Question #181 : Calculus 3

Find the coordinates of the curve function

when

Possible Answers:

Correct answer:

Explanation:

To find the coordinates, we evaluate the curve function for 

As such,

Example Question #4 : Parametric Curves

Find the coordinates of the curve function 

 when 

Possible Answers:

Correct answer:

Explanation:

To find the coordinates, we evaluate the curve function for

As such,

Example Question #5 : Parametric Curves

Find the equation of the line passing through the two points, given in parametric form:

Possible Answers:

Correct answer:

Explanation:

To find the equation of the line passing through these two points, we must first find the vector between them:

This was done by finding the difference between the x, y, and z components for the vectors. (This can be done in either order, it doesn't matter.)

Now, pick a point to be used in the equation of the line, as the initial point. We write the equation of line as follows:

The choice of initial point is arbitrary. 

Example Question #4 : Parametric Curves

Find the coordinate of the parametric curve when 

 

Possible Answers:

Correct answer:

Explanation:

To find the coordinates of the parametric curve we plug in for

.

As such the coordinates are

Example Question #2 : How To Find Velocity

The position of a particle is given by .  Find the velocity at .

Possible Answers:

Correct answer:

Explanation:

The velocity is given as the derivative of the position function, or

  .

We can use the quotient rule to find the derivative of the position function and then evaluate that at .  The quotient rule states that

 .  

In this case,  and .  

We can now substitute these values in to get

 .  

Evalusting this at  gives us .  

So the answer is .

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