Register
Login
Username
Password
Login
forgot your password?
Home
Forum
+0
Formulary
Maths
Help
Complex Numbers
Integral Calculus
Differential Calculus
Equations
Graphs
Linear Algebra
Number theory
Percent
Standard Functions
Statistics
Trigonometry
Unit Conversion
Units
About
Imprint
Privacy Policy
Terms of Service
Credits
Google+
Facebook
Contact Email
Post New Question
All Questions
+0
237167 Questions
0
1
0
+21
Algebra
Find
\sum_{k = 1}^{20} k(k^2 - 10k - 20)(k^2 + 1)
co1inqiu
Mar 7, 2025
0
1
1
+753
Algebra
Compute
1.11111 + 0.11111 + 0.01111 + 0.00111 + 0.00011 + 0.00001
●
crimefightingvigiI
Mar 7, 2025
0
1
1
+753
Algebra
Let a_1, a_2, a_3, \dots be an infinite geometric series with positive terms. If a_2 = 10, then find the smallest possible value of
a_1 + a_2 + a_3.
●
crimefightingvigiI
Mar 7, 2025
0
1
0
+753
Algebra
Let
a + ar + ar^2 + ar^3 + \dotsb
be an infinite geometric series. The sum of the series is 9. The sum of the cubes of all the terms is 36. Find the common ratio.
crimefightingvigiI
Mar 7, 2025
0
1
1
+753
Algebra
Let A = x^4 + x^3 + x^2 + x + 1 and B = x^4 - x^3 + x^2 - x + 1. Simplify A + B.
●
crimefightingvigiI
Mar 7, 2025
0
1
0
+1084
Algebra
The closed form sum of
12 \left[ 1 \cdot 2^2 \cdot 3 + 2 \cdot 3^2 \cdot 4 + \dots + n (n + 1)^2 (n + 2) \right]
for n \ge 1 is n(n + 1)(n + 2) p(n) for some polynomial p(n). Find p(n).
AnswerscorrectIy
Mar 7, 2025
0
1
0
+1084
Algebra
The sum
6 (1 \cdot 3 \cdot 5 + 2 \cdot 4 \cdot 6 + \dots + n(n + 2)(n + 4))
is equal to a polynomial f(n) for all n \ge 1.
Write f(n) as a polynomial with terms in descending order of n.
AnswerscorrectIy
Mar 7, 2025
0
1
1
+1084
Algebra
A sequence a_1, a_2, a_3, \dots of positive integers has the following properties:
* The first three terms are in geometric progression.
* The second, third, and fourth terms are in arithmetic progression.
* In general, for all $i\ge1$,
read more ..
●
AnswerscorrectIy
Mar 7, 2025
Mar 6, 2025
0
1
0
+1084
Algebra
A sequence of real numbers (a_n) is defined as follows: a_0 = 1, a_2 = 2, and
a_{n + 2} = \frac{a_{n + 1}}{a_n}
for n = 0, 1, 2, \dots. Find a_0 + a_1 + a_2 + \dots + a_{100}.
AnswerscorrectIy
Mar 6, 2025
0
1
1
+1084
Algebra
Let
P = 3^{1/3} \cdot 9^{1/9} \cdot 27^{1/27} \cdot 81^{1/81}.
Then P can be expressed in the form \sqrt[a]{b}, where $a$ and $b$ are positive integers. Find the smallest possible value of $a + b.$
●
AnswerscorrectIy
Mar 6, 2025
0
1
1
+1084
Algebra
Let
P = 2^{1/2} \cdot 4^{1/4} \cdot 8^{1/8} \cdot 16^{1/16}
Then P can be expressed in the form \sqrt[a]{b}, where $a$ and $b$ are positive integers. Find the smallest possible value of $a + b.$
●
AnswerscorrectIy
Mar 6, 2025
0
1
1
+75
Algebra
Let r be a real number such that |r| < 1. Express
\sum_{n = 0}^{\infty} n*r^n*(n + 1)*(n + 2)
in terms of r.
●
HumanBemg
Mar 6, 2025
0
1
1
+75
Algebra
Find
\sum_{k = 0}^{10} (k + 3) \cdot 2^k \cdot (k - 3)
●
HumanBemg
Mar 6, 2025
0
1
2
+75
Algebra
Simplify \frac{1 + 3 + 5 + ... + 1999 + 2001 + 2003}{2 + 4 + 6 + ... + 2000 + 2002 + 2004 + 2006 + 2008 + 2010}.
●
●
HumanBemg
Mar 6, 2025
+1
1
1
+75
Algebra
Find the sum
\frac{1}{7} + \frac{2}{7^2} + \frac{3}{7^3} + \frac{1}{7^4} + \frac{2}{7^5} + \frac{3}{7^6}
●
HumanBemg
Mar 6, 2025
Mar 5, 2025
0
1
1
+95
Algebra
Let a_1, a_2, a_3, \dots be an infinite geometric series with positive terms. If a_2 = 10, then find the smallest possible value of
a_1 + a_2 + a_3.
●
coIinqiu
Mar 5, 2025
0
1
1
+95
Algebra
Let
a + ar + ar^2 + ar^3 + \dotsb
be an infinite geometric series. The sum of the series is 9. The sum of the cubes of all the terms is 36. Find the common ratio.
●
coIinqiu
Mar 5, 2025
0
1
1
+95
Algebra
Let A = x^4 + x^3 + x^2 + x + 1 and B = x^4 - x^3 + x^2 - x + 1. Simplify A + B.
thatgirlaj
●
coIinqiu
Mar 5, 2025
Mar 4, 2025
0
3
1
+95
Algebra
Compute
1.11111 + 0.11111 + 0.01111 + 0.00111 + 0.00011 + 0.00001
●
coIinqiu
Mar 4, 2025
0
2
1
+95
Algebra
Simplify (x^4 + x^3 + x^2 + x + 1) + (x^4 - x^3 + x^2 - x + 1).
●
coIinqiu
Mar 4, 2025
0
2
0
+753
Algebra
Find all real numbers a such that the roots of the polynomial
x^3 - 3x^2 + 17x + a
form an arithmetic progression and are not all real.
crimefightingvigiI
Mar 4, 2025
0
1
0
+753
Algebra
Find the sum of the series
1 + \frac{1}{2} + \frac{1}{10} + \frac{1}{30} + \frac{1}{60} + ,..
where we alternately multiply by $\frac 12$ and $\frac 15$ and $\frac{1}{3}$ to get successive terms.
crimefightingvigiI
Mar 4, 2025
«
latest
9485
9484
..
2
1
»
Post New Question
2 Online Users
Top Users
+130458
CPhill
moderator
+37165
ElectricPavlov
+33654
Alan
moderator
+15048
asinus
moderator
+3146
admin
administrator
+2290
GingerAle
+1776
bader
+1734
blackpanther
+1721
parmen
+1556
kittykat
+1493
learnmgcat
Sticky Topics
Some guidelines for question askers.
What is Happening 5
Again a number puzzle. Multiply in writing.
Loads of fun printable number and logic puzzles
¤¤¤¤Welcome To Web2.0calc¤¤¤¤
How to display latex properly
Feature Questions 1 - Started 8th May 19
How to upload a picture.
If a question is ticked that does not mean you cannot continue it.
Should you consider anything before you answer a question?
Geometry Thread
PUZZLES
LaTex Coding
/calculator/bsh9ex1zxj
Historical post!
What is happening? Wrap #4
Great Questions to Learn From 2
Great Answers to Learn From
Reference Material
Information for new people.