+0

# Re-sending with clarity

+1
290
6
+105

Find the sum of this:

Sn = 1/1x2  +  1/2 x 3  +  1/3 x 4  +  1/n x (n+1)

[when using x in the denominator, i mean to use it as multiplication. 1/1x2 is bascially 1/2 or can be represented as 1/1 x (1+1)]

I appreciate all help!

I am in a 2de class and no one of 60 students solved it.

Thanks!

Mar 1, 2019

#4
+30088
+6

As follows:

Mar 2, 2019

#1
+23739
0

I believe the answer is  1

see :   https://www.mathsisfun.com/numbers/sigma-calculator.html

Mar 1, 2019
edited by ElectricPavlov  Mar 1, 2019
#2
+235
0

Oh ok so that last equation means an infinite number

Mar 1, 2019
#3
+23739
0

No.....the summation calculators can only go so far....so I put in 99999 to 'imitate' infinity....then the calc spits out all of the calculations....

the result was .9999900000000131      so I think it is safe to THINK/assume   ' 1 ' would be the answer.....

ElectricPavlov  Mar 1, 2019
#4
+30088
+6

As follows:

Alan Mar 2, 2019
#5
+111331
+3

Nice, Alan  !!!!

CPhill  Mar 2, 2019
#6
+105
+2

Great response! I have somewhat of an understanding of how you got the answer 1. I have also realized from this question that the materials necessary to solve it have not been taught at the grade 10 level, and am a little mad at my math teacher. I really was stuck on this one, great explanation once again!

Mar 2, 2019