Question

@ganeshie8
\[\huge \left(\begin{matrix}n+2 \\ 2\end{matrix}\right)\]
does this evaluate to 2n+1

Answer 1

\[\dfrac{(n-2)!}{(n-4)!2!}\]

Answer 2

\[\dfrac{(n-2)(n-3)(n-4)!}{(n-4)!2!}\]

Answer 3

(n-2)(n-3)/2!

Answer 4

yeah you get a square term

Answer 5

it cannot be simplified firther right?

Answer 6

further*

Answer 7

it can never become 2n+1

http://www.wolframalpha.com/input/?i=%28n-2%29+choose+2

Answer 8

okay

Answer 9

hos did u get \(\binom{n-2}{2}\) ?

Answer 10

there is a formula

Answer 11

k number of terms

Answer 12

for (a+b+c)^n that formula should give you

\[\binom{n+3-1}{3-1}\]

Answer 13

which is same as

\[\binom{n+2}{2}\]

Answer 14

right ?

Answer 15

yes