Summation?

[TheDon]

How the hell do I do this crap?

http://www.cs.ucf.edu/courses/cop3502/fall2010/assignments/SummationHW.pdf

I never learned this in trig or precalc.. I havent even gotten to fail the test on this yet in calc 1.

[The Swede]

Originally Posted by TheDon

How the hell do I do this crap?
I havent even gotten to fail the test on this yet in calc 1.

Think positive dude!

[TheDon]

ok.. well.. How do I do this crap so I can do the homework sheet. I'd like to get something accomplished this weekend since I still dont understand how to code my program that is due in .. 4 days

[jt20]

do you know C? anything is more than I know.

I will trade you math help for C help.

[TheDon]

I'm not a C guru by any means. I made a B in my intro to C class and am struggling in my comp sci 1 class

[jt20]

I am just taking an intro to C also. I haven't even looked at the assignments yet, its an online course - at my pace.

I am sure you can do it.

[TheDon]

pfft.. I can't...

what is your assignment I might be of some use

[jt20]

When you look at the summation notation:

i should enter your mind as 'index' or the indexing number /variable

n is the count, or the the final value of i

so if i=1 and n=5 there will be a math sentence that will be the sum of 5 separate values.

each value is the result of inputting the values of i , and some cases n, into the summation

[TheDon]

so like...#1 in the pdf I linked to..

the top is 2n, the thing to the right is "i" and it indexes at i=5

5(2n)+6(2n)....2n(2n)

?

[Crazy_Nate]

Originally Posted by jt20

When you look at the summation notation:

i should enter your mind as 'index' or the indexing number /variable

n is the count, or the the final value of i

so if i=1 and n=5 there will be a math sentence that will be the sum of 5 separate values.

each value is the result of inputting the values of i , and some cases n, into the summation

If you think of stuff in terms of for loops (ah, programming), it's very similar

sum = 0;
n=5;
for i = 1:n
sum = sum + some formula (dependent on n, x, y, z, or the current value of i)
end

Sorry...it's matlab notation, but very similar to C. The colon is basically a integer increment.

[jt20]

more like this:

sum(i, i = 5 .. 2*n) = 5+6+7+8 .. 2*n


in each value of the summation, i is increased by the value of 1

like: (i) + (i+1)+(i+2)....(i+n)

n is simply the final value that i (the indexing variable) will be for the summation

[Crazy_Nate]

Originally Posted by TheDon

so like...#1 in the pdf I linked to..

the top is 2n, the thing to the right is "i" and it indexes at i=5

5(2n)+6(2n)....2n(2n)

?

5 + 6 + 7 + 8 +...+ 2n

[TheDon]

Originally Posted by Crazy_Nate

5 + 6 + 7 + 8 +...+ 2n

that makes sense.

now if I am correct

stop at 100, (3i+4) index starts at ten

(3(10)+4) + (3(11)+4)+ ..... (3(100)+4)


?

[Crazy_Nate]

Originally Posted by TheDon

that makes sense.

now if I am correct

stop at 100, (3i+4) index starts at ten

(3(10)+4) + (3(11)+4)+ ..... (3(100)+4)


?

[TheDon]

wrong?