Expressing a Sum in Sigma Notation: 1 + (2/3) + (3/5) + (4/7) + (5/9)

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Homework Statement



"Express the following sum in sigma notation:

1 + (2/3) + (3/5) + (4/7) + (5/9)"

Homework Equations





The Attempt at a Solution



I've figured out what they all have in common (1+2=3, 2+3=5, 3+4=7, 4+5=9) but I've been searching through the book and on the internet how to express this.
 
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Suppose the kth term is n(k)/d(k). Can you find a pattern to how the numerator and denominator change with k?
 
I just figured it out. Apparently I just needed to finally ask for help.

The equation is (i/2i-1) with start i=1 and end at 5.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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