http://img24.imageshack.us/img24/6747/math16.png

--------

My attempts:

a) We need to show that if P(n) is true then P(n-1) also is.

, so

and

.

Not sure what to do now.

b)

Need to show . No idea what to do next.

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- Dec 6th 2009, 09:49 PMscorpion007Inductive proof
http://img24.imageshack.us/img24/6747/math16.png

--------

**My attempts:**

a) We need to show that if P(n) is true then P(n-1) also is.

, so

and

.

Not sure what to do now.

b)

Need to show . No idea what to do next. - Dec 7th 2009, 04:22 AMtonio
- Dec 7th 2009, 03:27 PMscorpion007
Thanks!

- Dec 7th 2009, 03:58 PMscorpion007
I noticed you multiplied both sides of the inequality by different amounts. Is it true in general that

? - Dec 8th 2009, 12:30 AMSeppel
- Dec 8th 2009, 12:47 AMscorpion007
Thanks Seppel!

Ah, but what if , like in the original question? Perhaps then it is true? - Dec 8th 2009, 01:11 AMDefunkt