## Precalculus (10th Edition)

Arithmetic Sum: $1375$
We are given the sequence: $\{n+2\}$ Compute the difference between two consecutive terms: $(k+2)-((k-1)+2)=(k+2)-(k+1)=1$ As the difference between any consecutive terms is constant, the sequence is ARITHMETIC. Determine its first element and common difference: $a_1=1+2=3$ $d=1$ Compute the sum of the first 50 terms: $S_n=\dfrac{n(2a_1+(n-1)d)}{2}$ $S_{50}=\dfrac{50(2(3)+(50-1)(1)}{2}=1375$