All AP Calculus AB Resources
Example Questions
Example Question #1 : Integrals
Write the equation of a tangent line to the given function at the point.
y = ln(x2) at (e, 3)
y = (2/e)(x – e)
y = (2/e)
y – 3 = ln(e2)(x – e)
y – 3 = (x – e)
y – 3 = (2/e)(x – e)
y – 3 = (2/e)(x – e)
To solve this, first find the derivative of the function (otherwise known as the slope).
y = ln(x2)
y' = (2x/(x2))
Then, to find the slope in respect to the given points (e, 3), plug in e.
y' = (2e)/(e2)
Simplify.
y'=(2/e)
The question asks to find the tangent line to the function at (e, 3), so use the point-slope formula and the points (e, 3).
y – 3 = (2/e)(x – e)
Example Question #1 : Numerical Approximations To Definite Integrals
Find the equation of the tangent line at when
The answer is
let's go ahead and cancel out the 's. This will simplify things.
this is the slope so let's use the point slope formula.
Example Question #11 : Integrals
Differentiate
We see the answer is after we simplify and use the quotient rule.
we could use the quotient rule immediatly but it is easier if we simplify first.
Example Question #11 : Integrals
Find
When taking limits to infinity, we usually only consider the highest exponents. In this case, the numerator has and the denominator has . Therefore, by cancellation, it becomes as approaches infinity. So the answer is .
Example Question #12 : Integrals
Evaluate:
cannot be determined
First, we can write out the first few terms of the sequence , where ranges from 1 to 3.
Notice that each term , is found by multiplying the previous term by . Therefore, this sequence is a geometric sequence with a common ratio of . We can find the sum of the terms in an infinite geometric sequence, provided that , where is the common ratio between the terms. Because in this problem, is indeed less than 1. Therefore, we can use the following formula to find the sum, , of an infinite geometric series.
The answer is .
Example Question #11 : Integrals
If then find .
The answer is 1.
Example Question #2 : Numerical Approximations To Definite Integrals
Find the equation of the tangent line at on graph
The answer is
(This is the slope. Now use the point-slope formula)
Example Question #13 : Integrals
Find the equation of the tangent line at (1,1) in
The answer is
(This is the slope. Now use the point-slope formula.)
Example Question #14 : Integrals
If then
The answer is .
We know that
so,
Example Question #7 : Numerical Approximations To Definite Integrals
1/2
2
1
1/4
does not exist
2
When we let x = 0 in our original limit, we obtain the 0/0 indeterminate form. Therefore, we can apply L'Hospital's Rule, which requires that we take the derivative of the numerator and denominator separately.
Apply the Chain Rule in the numerator and the Product Rule in the denominator.
If we again substitute x = 0, we still obtain the 0/0 indeterminate form. Thus, we can apply L'Hospital's Rule one more time.
If we now let x = 0, we can evaluate the limit.
The answer is 2.