Question

sigma

Answer 1

\[\sum_{x=1}^{25}\] K^2 -3k +4
what is the formula to solve if u dont have calculator

Answer 2

please help

Answer 3

\[\sum_{x=1}^{25}k^2-3\sum_{x=1}^{25}k+4\sum_{x=1}^{25}1\]

Answer 4

imran please go ahead, i have to get back to work

Answer 5

but this one is pretty easy
\[4\sum_{k=1}^{25}1=4\times 25=100\]

Answer 6

sum 1 to n of (1) is equal to n
sum 1 to n of (i) is equal to n(n+1)/2
sum 1 to n of (i^2) is equal to n(n+1)(2n+1)/6
um i think.

Answer 7

yes, agreed^

Answer 8

@curry you got this?

Answer 9

\[\sum_{k=1}^{n}k=\frac{n(n+1)}{2}\] so
\[-3\sum_{k=1}^{25}k=-3\times \frac{25\times 26}{2}\]

Answer 10

kind a

Answer 11

\[\sum_{k=1}^nk^2=\frac{n(n+1)(2n+1)}{6}\] so
\[\sum_{k=1}^{25}k^2=\frac{25(26)(51)}{6}\]

Answer 12

now you have all the numbers you need, grind it out with a calculator

Answer 13

should get 4650 if you do it right
http://www.wolframalpha.com/input/?i=sum+k+%3D+1+to+25+%28k^2-3k%2B4%29