All Calculus 3 Resources
Example Questions
Example Question #1 : Parametric Curves
Find the length of the parametric curve described by
from to .
None of the other answers
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 .
To find the coordinates, we set into the curve function.
We get
and thus
Example Question #1 : Parametric Curves
Find the coordinates of the curve function
when
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
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:
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
,
To find the coordinates of the parametric curve we plug in for
.
As such the coordinates are
Example Question #1 : Cross Product
Let , and .
Find .
We are trying to find the cross product between and .
Recall the formula for cross product.
If , and , then
.
Now apply this to our situation.
Example Question #1 : Cross Product
Let , and .
Find .
We are trying to find the cross product between and .
Recall the formula for cross product.
If , and , then
.
Now apply this to our situation.
Example Question #3 : Cross Product
True or False: The cross product can only be taken of two 3-dimensional vectors.
False
True
True
This is true. The cross product is defined this way. The dot product however can be taken for two vectors of dimension n (provided that both vectors are the same dimension).
Example Question #4 : Cross Product
Which of the following choices is true?
By definition, the order of the dot product of two vectors does not matter, as the final output is a scalar. However, the cross product of two vectors will change signs depending on the order that they are crossed. Therefore
.