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# Minor question, but cannot seem to solve watch

1. The first part of this question is:

Show that

So I started with:

Then surely

I'd go further but, this seems incorrect - could anybody guide me through this? I hate dealing with the factorial.
2. Amateur mistakes.

Edit: Just Kidding people.
3. (Original post by Femto)
The first part of this question is:

Show that

So I started with:

Then surely

I'd go further but, this seems incorrect - could anybody guide me through this? I hate dealing with the factorial.
Overcomplicating it a touch.

If you think about what actually means, you'll find that

How do you get a common denominator now?
4. (Original post by Femto)
I'd go further but, this seems incorrect - could anybody guide me through this? I hate dealing with the factorial.
. Do you see where to go from here?
5. (Original post by Straight up G)
Amateur mistakes.

Edit: Just Kidding people.
You're probably right to be honest
6. (Original post by Clarity Incognito)
Overcomplicating it a touch.

If you think about what actually means, you'll find that

How do you get a common denominator now?
Hmm, I'm sorry I cannot see what the common denominator would be unless it's r!? Would you mind explaining to me how you got the (2).(1) in the denominator?
7. (Original post by Femto)
Hmm, I'm sorry I cannot see what the common denominator would be unless it's r!? Would you mind explaining to me how you got the (2).(1) in the denominator?
From the definition of a factorial, 1!=1, 2!=2x1, 3!=3x2x1, ...., n!=nx(n-1)x(n-2)x...x3x2x1.

Yeah, they both have r! in the denominator and you want to muultiply one of the fractions by something else so that they both have the same denominator, then you simplify your expression.
8. (Original post by Clarity Incognito)
From the definition of a factorial, 1!=1, 2!=2x1, 3!=3x2x1, ...., n!=nx(n-1)x(n-2)x...x3x2x1.

Yeah, they both have r! in the denominator and you want to muultiply one of the fractions by something else so that they both have the same denominator, then you simplify your expression.
Would it become?

9. (Original post by Clarity Incognito)
From the definition of a factorial, 1!=1, 2!=2x1, 3!=3x2x1, ...., n!=nx(n-1)x(n-2)x...x3x2x1.

Yeah, they both have r! in the denominator and you want to muultiply one of the fractions by something else so that they both have the same denominator, then you simplify your expression.
This assumes that you're dealing with integer factorials!

(Original post by Femto)
Would it become?

Did you see my post?
10. (Original post by BJack)
This assumes that you're dealing with integer factorials!

Did you see my post?
Yes I am aware of it, thanks very much for your reply I am doing this wrong right?
11. (Original post by BJack)
This assumes that you're dealing with integer factorials!
Haha, ok, my method was purely for positive integers but it can be easily adapted nonetheless to produce the same result! Good shout nonetheless, it just looked like an A level question to me!
12. (Original post by Femto)
Yes I am aware of it, thanks very much for your reply I am doing this wrong right?
You should probably write it out as

rather than

for each stage. Apart from that, your approach is fine, though expanding the factorials is unnecessary when you can just factorize the resulting numerator almost immediately.
13. (Original post by BJack)
You should probably write it out as

rather than

for each stage. Apart from that, your approach is fine, though expanding the factorials is unnecessary when you can just factorize the resulting numerator almost immediately.
Yeah I see what you mean, but I'm struggling to go from where I left off in the OP
14. (Original post by Femto)
Yeah I see what you mean, but I'm struggling to go from where I left off in the OP
15. (Original post by Straight up G)
Amateur mistakes.

Edit: Just Kidding people.
Noob.
16. (Original post by awais590)
Noob.
What you talkin bout waisy you dont talk to Don like that
17. (Original post by Straight up G)
What you talkin bout waisy you dont talk to Don like that
18. (Original post by BJack)
Aah yes of course!! Thank you very much!

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