Curse

Shadow Slave · May 14, 2009, 06:22 PM // 18:22

Greetings GWG ~

I am busy trying to revise for an exam I have tomorrow morning, and could use your help..

Having not studied Maths beyond GCSE level, these kind of calculations always seem to trip me up.

So, my question is simple - in what order am I supposed to tackle this kind of equation in order to get the answer provided.

I've entered this into my calculator as seperate calculations, or all together..in as many ways as I can think of, and still come up with answers that are nowhere near.

Not really sure where I'm going wrong *sigh*

I have a few variations of this same question, and each one is getting me ><

Help me Guru-man!

Empress Amarox · May 14, 2009, 06:30 PM // 18:30

Right well, under the assumption that it's a quadratic (from memory), you may find this useful: http://en.wikipedia.org/wiki/Quadratic_equation

I specifically remember the quadratic formula:

If that's not it, I'm sorry... It's been awhile.

Winterclaw · May 14, 2009, 06:45 PM // 18:45

First of all, is that 7 times the square root of some number or the 7th root of that number. Secondly, is that (24.2/16.1 -1) in the square or (24.2/16.1) in the square minus 1.

I'm reading it as the 7th root of (24.2/16.1) and then subtract one from that.

glacialphoenix · May 14, 2009, 06:48 PM // 18:48

Er. I do believe the -1 is separate from the rest. I got 0.0599, which would round off to 0.06.

24.2/16.1 first, root 7 that, THEN -1.

EDIT: You might want to make sure you didn't make a mistake when keying it in, too.

Shadow Slave · May 14, 2009, 06:54 PM // 18:54

Exactly lol...that's my question ><

I've tried it every way I can think of and have yet to arrive at 0.06...

A similar example, answered manually:

3.38 x (1+G)^5 (to the power of 5) = 5.4

= 1+G x (5.4/3.38) 1/5

= 1+G = 1.098

= G = 0.098 or 9.8%

Now again lol -nothing I have tried gives me 0.098 as my answer. I'm going wrong somewhere ><

Master Fuhon · May 14, 2009, 07:03 PM // 19:03

Quote:

Originally Posted by glacialphoenix

Er. I do believe the -1 is separate from the rest. I got 0.0599, which would round off to 0.06.

24.2/16.1 first, root 7 that, THEN -1.

This explanation works.

((24.2/16.1)^(1/7))-1 = 0.05995...

Xenomortis · May 14, 2009, 07:06 PM // 19:06

That small 7 outside the root sign means, the 7th root of [stuff].
Tricky for me to help you with the calculator stuff, as I don't know what type of calculator you have.

That can be rewritten, more easily for use with a calculator, as:

(24.2/16.1) ^ (1/7) - 1
which will give 0.0599471534... which is 0.06 to 1 signficant figure.

So, to get that answer:
Calculate 24.2/16.1
Take the 7th root of that (or raise it to the power of 1/7).
Minus 1.

If you have a half decent calculator, you should be able to type that all in as a linear expression (like my original statement). If you have a calculator like mine, you can even type it all in as you originally gave it.

Hard to give strong advice though, as I don't actually know where your problem lies.

Shadow Slave · May 14, 2009, 07:07 PM // 19:07

Huzzah! got it lol ~ It was all to do with how I was entering it in my calculator I think.

I found a function I never knew my calculator had, and hey presto!

Cheers Phoenix and Fuhon

((24.2/16.1)^(1/7))-1 is what I was after.

Edit: Brownie points for you too Xeno!

Xenomortis · May 14, 2009, 07:14 PM // 19:14

Knowing how to use your calculator correctly is vitally important. Too often I've seen people fail at something, not knowing why. The problem isn't their understanding of the question, but that they miss a vital step in entering things into their calculator.

May I ask what kind of exam you're frantically revising for?

glacialphoenix · May 14, 2009, 07:17 PM // 19:17

Quote:

Originally Posted by Xenomortis

The problem isn't their understanding of the question, but that they miss a vital step in entering things into their calculator.

My students do this a lot - key in something, forget a bracket, oops, there goes the entire question.

@ Shadow: glad it helped, all the best for your exam!

Shadow Slave · May 14, 2009, 07:33 PM // 19:33

^^ Thanks guys

The exam is Financial Management.

This calculation is part of the Dividend Valuation Model ~ looking at previous years dividends, determining the growth rate, and stating whether the shares are a good buy at their current market price

Xenomortis · May 14, 2009, 07:44 PM // 19:44

Hmm... I would've expected a required maths level beyond GCSE for something like that.

Anyway, make sure you know how to use your calculator properly and remember to use brackets where necessary.
If your calculator does long linear operations, then it will also correctly follow the Order of Operations (brackets, exponents, multiplication, addition).