2.) For each sum find: a.) the number of terms, b.) the first term, c.) the last term, and d.) evaluate the sum. (4 pts each) A. 5 B. 8 E (3n+1) E (2n/3) n=1 n=1
\[\sum_{n=1}^{5}\left( 3n+1 \right)\] no of terms=5 first term =3*1+1=4 last term=3*5+1=16 \[n=5,\sum=\frac{ n }{ 2 }\left( a+l \right)=\frac{ 5 }{ 2 }\left( 4+16 \right)=?\]
50 ?
correct.
So then for the next one? I can do the same. Can you help me set that one up?
yes you should proceed in the same way,i will help.
Ok, I'm going to attempt it, one second!
I'm a little confused.. No. of terms= 8
First term is? 2*3+1?
\[\sum_{n=1}^{8}\frac{ 2n }{ 3 }\] no .of terms n=8 first term \[a=\frac{ 2*1 }{ 3 }=\frac{ 2 }{ 3 }\] last term \[l=\frac{ 2*8 }{ 3 }=\frac{ 16 }{ 3 }\] use the above given formula and find sum.
Could you go into slightly more detail. n=8 E= 8/2(2/3+16/3)
So the answer would be around 24?
@surjithayer
correct.
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