Es ist
\( \sum_{k=0}^{20} a_k \) \( = \sum_{k=0}^{20} (2 + \frac{k}{10}) \) \( = (\sum_{k=0}^{20} 2) + (\sum_{k=0}^{20} \frac{k}{10}) \) \( = 2 \cdot (\sum_{k=0}^{20} 1 ) + \frac{1}{10} \cdot (\sum_{k=0}^{20} k) \) \( = 2 \cdot 21 + \frac{1}{10} \cdot \frac{20 \cdot 21}{2} = 63 \)
und
\( \sum_{k=60}^{100} a_k \) \( = \sum_{k=0}^{40} a_{k+60} \) \( = \sum_{k=0}^{40} (2 + \frac{k+60}{10}) \) \( = \sum_{k=0}^{40} (8 + \frac{k}{10}) \) \( = (\sum_{k=0}^{40} 8) + (\sum_{k=0}^{40} \frac{k}{10}) \) \( = 8 \cdot (\sum_{k=0}^{40} 1) + \frac{1}{10} \cdot (\sum_{k=0}^{40} k) \) \( = 8 \cdot 41 + \frac{1}{10} \cdot \frac{40 \cdot 41}{2} = 410 \)
Student, Punkte: 7.02K