Find the partial sum of the arithmetic sequence with the given first term and common difference
-$\mathrm{s}_{5}, \mathrm{a}_{1}=2, \mathrm{~d}=1$
A) 20
B) 7
C) 2
D) 10

Question

Find the partial sum of the arithmetic sequence with the given first term and common difference  
-$\mathrm{s}_{5}, \mathrm{a}_{1}=2, \mathrm{~d}=1$
A) 20
B) 7
C) 2
D) 10

Quizplus · Accepted Answer

The formula for the partial sum of an arithmetic sequence is $S_n = \frac{n}{2}(2a_1 + (n-1)d)$, where $S_n$ is the partial sum of the first $n$ terms, $a_1$ is the first term, $d$ is the common difference, and $n$ is the number of terms. Plugging in the given values ($n=5$, $a_1=2$, $d=1$), we get $S_5 = \frac{5}{2}(2*2 + (5-1)*1) = \frac{5}{2}(4 + 4) = \frac{5}{2} * 8 = 20$.

Find the Partial Sum of the Arithmetic Sequence with the Given