All AP Calculus BC Resources
Example Questions
Example Question #4 :Alternating Series With Error Bound
Determine whether the series converges or diverges:
The series may be convergent, divergent, or conditionally convergent.
The series is (absolutely) convergent.
The series is conditionally convergent.
The series is divergent.
The series is divergent.
To determine whether the series converges or diverges, we must use the Alternating Series test, which states that for
- andwherefor all n - to converge,
must equal zero andmust be a decreasing series.
For our series,
because it behaves like
.
The test fails becauseso we do not need to check the second condition of the test.
The series is divergent.
Example Question #1 :Abstract Algebra
Which of the following series does not converge?
We can show that the seriesdiverges using the ratio test.
will dominate oversince it's a higher order term. Clearly, L will not be less than, which is necessary for absolute convergence.
Alternatively, it's clear thatis much greater than, and thus havingin the numerator will make the series diverge by thelimit test (since the terms clearly don't converge to zero).
The other series will converge by alternating series test, ratio test, geometric series, and comparison tests.
Example Question #1 :有限公司ncepts Of Convergence And Divergence
One of the following infinite series CONVERGES. Which is it?
None of the others converge.
converges due to the comparison test.
We start with the equation. Sincefor all values of k, we can multiply both side of the equation by the inequality and getfor all values of k. Sinceis a convergent p-series with,hence also converges by the comparison test.
Example Question #1 :P Series
Determine the nature of convergence of the series having the general term:
The series is convergent.
The series is divergent.
The series is convergent.
We will use the Limit Comparison Test to establish this result.
We need to note that the following limit
goes to 1 as n goes to infinity.
Therefore the series have the same nature. They either converge or diverge at the same time.
We will focus on the series:
.
We know that this series is convergent because it is a p-series. (Remember that
converges if p>1 and we have p=3/2 which is greater that one in this case)
By the Limit Comparison Test, we deduce that the series is convergent, and that is what we needed to show.
Example Question #1 :P Series
Determine if the series converges or diverges. You do not need to find the sum.
Diverges
There is not enough information to decide convergence.
Neither converges nor diverges.
有限公司nditionally converges.
有限公司nverges
有限公司nverges
We can compare this to the serieswhich we know converges by the p-series test.
To figure this out, let's first compareto. For any number n,will be larger than.
There is a rule in math that if you take the reciprocal of each term in an inequality, you are allowed to flip the signs.
Thus,turns into
.
And so, becauseconverges, thus our series also converges.
Example Question #1 :Harmonic Series
Which of the following tests will help determine whetheris convergent or divergent, and why?
Integral Test: The improper integral determines that the harmonic series diverge.
Nth Term Test: The series diverge because the limit asgoes to infinity is zero.
P-Series Test: The summation converges since.
Divergence Test: Since limit of the series approaches zero, the series must converge.
Root Test: Since the limit asapproaches to infinity is zero, the series is convergent.
Integral Test: The improper integral determines that the harmonic series diverge.
The seriesis a harmonic series.
The Nth term test and the Divergent test may not be used to determine whether this series converges, since this is a special case. The root test also does not apply in this scenario.
According the the P-series Test,must converge only if. Therefore this could be a valid test, but a wrong definition as the answer choice since the series diverge for.
This leaves us with the Integral Test.
由于反常积分发散,那么series.
Example Question #1 :Alternating Series
Does the seriesconverge conditionally, absolutely, or diverge?
Cannot tell with the given information.
Does not exist.
有限公司nverge Absolutely.
Diverges.
有限公司nverge Conditionally.
有限公司nverge Conditionally.
The series converges conditionally.
The absolute values of the seriesis a divergent p-series with.
However, the the limit of the sequenceand it is a decreasing sequence.
Therefore, by the alternating series test, the series converges conditionally.
Example Question #11 :Series Of Constants
True or False, a-series cannot be tested conclusively using the ratio test.
True
False
True
We cannot test for convergence of a-series using the ratio test. Observe,
For the series,
.
Since this limit isregardless of the value for, the ratio test is inconclusive.
Example Question #1 :Ratio Test And Comparing Series
Determine if the following series is divergent, convergent or neither.
Neither
Inconclusive
有限公司nvergent
Divergent
Both
有限公司nvergent
In order to figure out if
is divergent, convergent or neither, we need to use the ratio test.
Remember that the ratio test is as follows.
Suppose we have a series. We define,
Then if
, the series is absolutely convergent.
, the series is divergent.
, the series may be divergent, conditionally convergent, or absolutely convergent.
Now lets apply the ratio test to our problem.
Let
and
Now
Now lets simplify this expression to
.
Since
.
We have sufficient evidence to conclude that the series is convergent.
Example Question #1 :Limits Of Sequences
Determine if the following series is divergent, convergent or neither.
Both
Inconclusive
Neither
Divergent
有限公司nvergent
Divergent
In order to figure if
is convergent, divergent or neither, we need to use the ratio test.
Remember that the ratio test is as follows.
Suppose we have a series. We define,
Then if
, the series is absolutely convergent.
, the series is divergent.
, the series may be divergent, conditionally convergent, or absolutely convergent.
Now lets apply the ratio test to our problem.
Let
and
Now
.
Now lets simplify this expression to
.
Since,
we have sufficient evidence to conclude that the series is divergent.