Arithmetic progression homework

Michael_Light
Messages
112
Reaction score
0

Homework Statement



Need help with number (9)..
DSC00560.jpg


Homework Equations





The Attempt at a Solution



Can anyone give me some hints? Thanks.
 
Physics news on Phys.org
Think. Subtract.
 


Sn=3n2 + 4n
Hint:
S1=3+4=7
S2=12+8=20
 

Thread 'Finding the number of ways to arrange identical balls in a circle (3 different colors)'

I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
View full post »

Thread 'Greatest possible value of a constant in polynomial'

Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
View full post »

Similar threads

Find α+β+αβ: 7 "Solving for α+β+αβ in Arithmetic Progression
Replies
24
Views
3K
Triangle determined by arithmetic and geometric sequences
Replies
7
Views
2K
How to Solve Arithmetic Sequence Problems
Replies
1
Views
2K
What Is the Common Difference in This Arithmetic Progression?
Replies
3
Views
2K
Arithmetic progression used to determine geometric progression
Replies
3
Views
2K
Question about arithmetic progressions
Replies
3
Views
2K
Solving Arithmetic Progression and Combinations: Question on Number Theory
Replies
9
Views
2K
Arithmetic Progression - show that question
Replies
5
Views
2K
Arithmetic Progression: Find Common Difference with Given First Term and Ratio
Replies
3
Views
2K
Arithmetic Progression Problem
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top