Given sum_(n=1)^250 (1000-n)
The sum for an arithmetic sequence is
S_n=n/2(a_1+a_n)
The number of terms for the sequence is n=250.
The first term of the sequence is a_1=1000-1=999.
The last term of the sequence is a_250=1000-250=750.
S_250=250/2(999+750)
S_250=125(1749)
S_250=218,625
No comments:
Post a Comment