A little math problem for you guys

[mayorredbeard]

Express this sum in sigma notation:

1-(1/4)+(1/9)-(1/16)+(1/25)

:-D

 

[JogaBonito1502]

K. I'm up to it. I'm not going to cheat. I don't know if there is a answer or not but I'll see. There should be. I'll post my answer edited in white.

edit: Got it!

5
E (1/i^2) * (-1^(i+1))
i=1

 

[Rubber314Chicken]

the sum of numbers from i=1 to i=5 of 1/-((-i)^2)

I don't know how to make it look normal so I wrote it like you say it.

 

[JogaBonito1502]

RubberChicken, I'm not sure if that works. That way you always get a negative number.

 

[Rubber314Chicken]

RubberChicken, I'm not sure if that works. That way you always get a negative number.

shoot, right... I was thinking 2 to the i, not i to the 2nd

 

[mayorredbeard]

shoot, right... I was thinking 2 to the i, not i to the 2nd

Nice try.

Hint: To alternate positive and negative numbers put (-1)^x. When x is odd its negative, and when x is even its positive. Then if you wanted to reverse this you could put a negative in front of that. I hope I didn't just give the answer away completely ;-P

 

[ghostFL]

The ultimate, true answer is as followed in white...


42

 

[Bobert93]

/\lol hahaha

but seriously , im in grade 9 i dont have a clue what ur talking about

 

[Fanatic4Christ]

wt heck kinda math is this if you guys dont mind me asking =D