Question

Find the sum of the first 50 terms of the sequence below.
An = 3n + 2

Answer 1

Insert the summation symbol.
siqma An=?

Answer 2

\[\sum_{n=1}^{50}a_n\]

Answer 3

well

n = 1 you get 5

n = 2 you get 8

n = 3 you get 11

the sequence is arithmetic

so find the 50th term when n = 50

then its 1st term + last term times the number of terms divided by 2.

sum = n/2( 1st + last)

Answer 4

Okay apply it on RHS.

Answer 5

what's that

Answer 6

And remember sigma(n+k)=sigma n+sigma k

Answer 7

for An i got An = 152 is that right

Answer 8

well thats

\[a_{50} = 152\]

Answer 9

and I got 3925 as the sum is that right?

Answer 10

@campbell_st @AravindG

Answer 11

Looks good :)