All AP Calculus AB Resources
Example Questions
Example Question #104 : Chain Rule And Implicit Differentiation
Find the derivative of .
This problem requires us to use the chain rule twice.
First, take the derivative of .
Now substitute for and multiply by the derivative of .
is our final answer.
Example Question #103 : Chain Rule And Implicit Differentiation
Given , calculate the slope of the tangent line when .
The slope of the tangent line is found by taking the derivative. In this case, because we don't have the function defined explicitly, we'll have to use implicit differentiation to get
Where the first two terms come from product rule. Factoring out a dy/dx and moving the other terms to the right, we get
And solving for dy/dx, we get
.
As the problem doesn't give us a y value, we'll need to go back to the original equation to find it. Plugging in x = 1, we have
And simplifying yields
Plugging the point (1, 3) into our expression for dy/dx, we have
Alternatively, this expression could have been solved for explicitly by factoring a y term out. Note,
And thus, . Using quotient rule, we know the derivative of this
is .
Evaluated at x=1, this becomes
Example Question #104 : Chain Rule And Implicit Differentiation
For the equation,, find .
Finding for an equation of this complexity requires implicit differentiation.
We need to take the derivative of both sides with respect to x.
For , we will apply the product rule and chain rule.
The product rule is as follows: , where f and g are the two factors of the expression. In this case, and will be and respectively. When we find , we will use the chain rule. This is because the inside of the contains variables other than x. Recall that the derivative of with respect to is .
This all means that
Observe that which is just 1.
Applying all this we find that the derivative of is
.
Now we will find the derivative of the next term, . This will also require product rule and chain rule. For this product rule, and will be and respectively.
will be the derivative of with respect to , which is .
will require the chain rule. The derivative of is , and the derivative of with respect to is .
This means that .
Assembling the power rule gives the derivative of the second term as
For the right hand side of the equation, the derivative of is still .
Putting all three derivatives together into one equation yields the following:
The next step in implicit differentiation is solving for . To do this we move all terms that have no factor to one side, and all terms with a factor to the other side.
In this case, we already have all terms on the left, so we will move the non- terms to the right side.
Now we can pull the common factor of out of the left side. We will then divide by what is remaining.
This is the final answer. It cannot be simplified.
Example Question #201 : Computation Of The Derivative
Let . Find the derivative, .
The shortest and simplest way to find the derivative of this function is to use the Chain Rule. The Chain Rule definition is . This is somewhat difficult to read and work with at first. Putting it in words helps though. What this definition states is that the derivative of "layered functions" is the derivative of the outer function times the derivative of the inner function. When I say "layered functions", I mean functions inside other functions. In this problem, we have the function, , inside of a cubic function ,, where is holding the place of the inner function. The outer function is the cubic, while the inner function is the.
Applying the chain rule to this pair of layers means applying the power rule to the outer function, then multiplying it by the derivative of the inner function. Doing so gives
We will need to find the derivative of the inner function, , but first we will write the expression using the actual inner function.
.
To find , we will take the derivative of the two terms inside separately.
The derivative of is .
The derivative of is another Chain Rule. We take the derivative of outer function, , to get of the same inner function. Then we multiply it by the derivative of the inner function. The derivative of is .
Putting these together we get the following for the derivative of:
Simplifying it, we get
Putting this at the end of the original chain rule we have
This cannot be simplified, so it is the final answer
Example Question #101 : Chain Rule And Implicit Differentiation
Find if
According to the chain rule .
Therefore, the derivative we are looking for will be
Example Question #102 : Chain Rule And Implicit Differentiation
Use implicit differentiation to calculate for the following equation:
Differentiate both sides of the equation:
Simplify:
Use implicit differentiation to evaluate :
Simplify:
Subtract from both sides of the equation:
Divide both sides of the equation by siny:
Simplify:
Solution:
Example Question #1 : Interpretations And Properties Of Definite Integrals
If f(1) = 12, f' is continuous, and the integral from 1 to 4 of f'(x)dx = 16, what is the value of f(4)?
27
12
28
4
16
28
You are provided f(1) and are told to find the value of f(4). By the FTC, the following follows:
(integral from 1 to 4 of f'(x)dx) + f(1) = f(4)
16 + 12 = 28
Example Question #1 : Interpretations And Properties Of Definite Integrals
Find the limit.
lim as n approaches infiniti of ((4n3) – 6n)/((n3) – 2n2 + 6)
–6
4
0
1
nonexistent
4
lim as n approaches infiniti of ((4n3) – 6n)/((n3) – 2n2 + 6)
Use L'Hopitals rule to find the limit.
lim as n approaches infiniti of ((4n3) – 6n)/((n3) – 2n2 + 6)
lim as n approaches infiniti of ((12n2) – 6)/((3n2) – 4n + 6)
lim as n approaches infiniti of 24n/(6n – 4)
lim as n approaches infiniti of 24/6
The limit approaches 4.
Example Question #1 : Interpretations And Properties Of Definite Integrals
If a particle's movement is represented by , then when is the velocity equal to zero?
The answer is seconds.
now set because that is what the question is asking for.
seconds
Example Question #3 : Interpretations And Properties Of Definite Integrals
A particle's movement is represented by
At what time is the velocity at it's greatest?
The answer is at 6 seconds.
We can see that this equation will look like a upside down parabola so we know there will be only one maximum.
Now we set to find the local maximum.
seconds
Certified Tutor