All AP Calculus BC Resources
Example Questions
Example Question #1 : Parametric, Polar, And Vector Functions
Rewrite as a Cartesian equation:
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 #2 : Parametric, Polar, And Vector Functions
Rewrite as a Cartesian equation:
, so
This makes the Cartesian equation
.
Example Question #1 : Functions, Graphs, And Limits
If and , what is in terms of (rectangular form)?
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 #1 : Parametric Form
Given and , what is the arc length between ?
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 #2 : Parametric Form
Given and , what is the length of the arc from ?
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 #3 : Parametric, Polar, And Vector Functions
Find the length of the following parametric curve
, , .
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
Example Question #1 : Parametric Form
Find dy/dx at the point corresponding to the given value of the parameter without eliminating the parameter:
The formula for dy/dx for parametric equations is given as:
From the problem statement:
If we plug these into the above equation we end up with:
If we plug in our given value for t, we end up with:
This is one of the answer choices.
Example Question #5 : Parametric Form
Draw the graph of from .
Between and , the radius approaches from .
From to the radius goes from to .
Between and , the curve is redrawn in the opposite quadrant, the first quadrant as the radius approaches .
From and , the curve is redrawn in the second quadrant as the radius approaches from .
Example Question #1 : Parametric Form
Draw the graph of where .
Because this function has a period of , the amplitude of the graph appear at a reference angle of (angles halfway between the angles of the axes).
Between and the radius approaches 1 from 0.
Between and , the radius approaches 0 from 1.
From to the radius approaches -1 from 0 and is drawn in the opposite quadrant, the fourth quadrant because it has a negative radius.
Between and , the radius approaches 0 from -1, and is also drawn in the fourth quadrant.
From and , the radius approaches 1 from 0. Between and , the radius approaches 0 from 1.
Then between and the radius approaches -1 from 0. Because it is a negative radius, it is drawn in the opposite quadrant, the second quadrant. Likewise, as the radius approaches 0 from -1. Between and , the curve is drawn in the second quadrant.
Example Question #261 : Parametric, Polar, And Vector
Graph where .
Taking the graph of , we only want the areas in the positive first quadrant because the radius is squared and cannot be negative.
This leaves us with the areas from to , to , and to .
Then, when we take the square root of the radius, we get both a positive and negative answer with a maximum and minimum radius of .
To draw the graph, the radius is 1 at and traces to 0 at . As well, the negative part of the radius starts at -1 and traces to zero in the opposite quadrant, the third quadrant.
From to , the curves are traced from 0 to 1 and 0 to -1 in the fourth quadrant. Following this pattern, the graph is redrawn again from the areas included in to .