Qwertyuiop[]
Junior Member
- Joined
- Jun 1, 2022
- Messages
- 123
Hi, I want to express this sum [imath]\sum_{k=2}^{n} \binom{n}{k} 3^\frac{n-k}{2} (-1)^{2k+3}[/imath] in the binomial form [imath](x+y)^n[/imath]. So i simplified the expression and got here but not sure if it's correct, [imath]- \sum_{k=2}^{n}\binom{n}{k} \sqrt{3}^{n-k} (1)^{k}[/imath] I can write this as [imath](\sqrt{3} + 1)^{n}[/imath] but the problem is k=2 and not 0 so i have 2 questions:
1) Will this equal [imath](\sqrt{3} + 1)^{n}[/imath] if k does not equal 0 in our case k=2
2) if not then how i can write this in [imath](x+y)^n[/imath] form when k is not 0 ?
1) Will this equal [imath](\sqrt{3} + 1)^{n}[/imath] if k does not equal 0 in our case k=2
2) if not then how i can write this in [imath](x+y)^n[/imath] form when k is not 0 ?