How is sigma notation used to find the value of a series?
• What key features are unique to the graphs of sequences and series?
• How can the average rate of change be found using a discrete graph?
• What are recursive and explicit functions?

Question

How is sigma notation used to find the value of a series?
•	What key features are unique to the graphs of sequences and series?
•	How can the average rate of change be found using a discrete graph?
•	What are recursive and explicit functions?

anonymous · Answer

@phi

anonymous · Answer

how you determine the sigma notation for a series depends on what information you're given, but it's almost always a shorthand for the sum of a large series of numbers: 

The number above the sigma is the upper bound of the summation (or the last variable value in the series), and the equality on the bottom (something like x=1 is the lower bound, or the first variable value in the series). 

It's usually not a trial-and-error formula - you should be able to use the given information to set up a summation (sigma) formula. But you're right that arithmetic sequences sometimes play arole in sigma notation - indeed the material to the right of the sigma (the expression contains the variable whose bounds are given above and below the sigma) is an arithmetic sequence that can be used to find the value in the series for a given value of the variable (what you rightly call the "nth term"). 

Limits can also be used (usually on top) - to say "as x approaches 0" or "as x approaches infinity" - to find the ultimate limit of the function on the right. 
 

Hope this helps!

anonymous · Answer

which question is this @o_dats_him

anonymous · Answer

How is sigma notation used to find the value of a series?
•	What key features are unique to the graphs of sequences and series?
•	How can the average rate of change be found using a discrete graph?
•	What are recursive and explicit functions?

anonymous · Answer

oh I aint know that was all 4 questions @o_dats_him  can u help me with ome more please ill post them on the wall and jus tag you to them if that's ok with you

anonymous · Answer

im confused  still need help can u break it up for me @o_dats_him

anonymous · Answer

can u explain this better @phi

anonymous · Answer

@amistre64  can u help me

anonymous · Answer

@epoweritheta  can u explain this to me a little better like the other kid put all 4 questions together n I don't understand It

epoweritheta · Answer

recursive function :
eg:
f(x+1)=2f(x) ;f(0)=2
find f(5)?

explicit fnctin:
eg:
f(x)=2^x