MATH HELP

[woodpecker 0]

I guess I'm a fucking moron because I cant get this to work. Please help!

I'm trying to figure out a monthly payment from a loan (java assignment) and cant get the equation to work.

here is the equation I have:

monthly payment =

principal *

(interest rate / 12)
---------------------
1 - (1 + (interest rate / 12))


but when I use this formula I keep getting the prinicpal in negative?

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[Peej 0]

Wow, thank you for that, i haven't felt that stupid since i finished watching Syriana

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[woodpecker 0]

So I'm guessing you dont know either?

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[labrys 0]

I think what you need is:

principal *

(interest rate / 12)
---------------------
1 - (1 + (interest rate / 12)^-N)

N is the number of months for the loan

Owned by Remi #?

[woodpecker 0]

yup, thats what i was missing.

thanks for the help.

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[Peej 0]

Quote

So I'm guessing you dont know either?

Uh huh

Advertisio Rodriguez / Sky

[Richards 0]

I am presuming the rate is definitely compounded monthly (be absolutely sure of that before you proceed) After that it is reasonably simple but you have an error in your formula.

PMT= (PV*r)/{1-1/[(1+r)^n]}

n= number of periods
PMT=Payment
PV=Present Value (principle)
R= APR (annualised interest rate)
r=R/12

You should be able to confirm your answer using the TVOM tables in any finance text or by using a financial calculator (warning if all you inputs in a financial calculator are positive it will give the answer as a negative even though it is positive).

If you can, post the full question and I can at least show you the process and confirm your answer.

Richards

My biggest handicap is that sometimes the hole in the front of my head operates a tad bit faster than the grey matter contained within.

[freeflir29 0]

I would be glad to help..........However, did you see my post about me taking a "Math for Liberal Arts Majors" class.

[rehmwa 2]

Quote

I think what you need is:

principal *

(interest rate / 12)
---------------------
1 - (1 + (interest rate / 12)^-N)

N is the number of months for the loan

this just cancels the 1's

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[labrys 0]

No, it doesn't.

Owned by Remi #?

[woodpecker 0]

K, guess I'm really stupid when it comes to this then because I still am not getting the correct answer.

principal = 5000
interest rate = .075
term = 12 months

The answer is actually 433.79 but I have no idea how to get this answer. Can some one "dumb" this up for me.

The best part is after I figure this math out, I get to complete a "while loop" to run the complete program. Yay for me.

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[Richards 0]

r=R/12
=.075/12=.00625

PMT=(5000*.00625)/{1-1/[(1+.00625)^12]}=433.787084

Be very carefull with the BEDMAS.

Conversely you should be able to use the financial funcyions on a calculator.

Richards

My biggest handicap is that sometimes the hole in the front of my head operates a tad bit faster than the grey matter contained within.

[labrys 0]

The top of your fraction is .075/12 or .00625

Then start with the stuff inside the inner parens in the demoninator first:

.075/12 = .00625

Then add the 1:

1+.00625 = 1.00625

That to the negative power of the number of months:

1.00625 ^ -12 = .92796

Subtract that answer from 1

1-.928 = .07204

So your fraction is .00625 / .07204 = .08675

Multiply times the principal:

5000 * .08675 = 433.7867

Owned by Remi #?

[rehmwa 2]

Quote

No, it doesn't.

yes it does, maybe you are using your parenthesis wrong

...
Driving is a one dimensional activity - a monkey can do it - being proud of your driving abilities is like being proud of being able to put on pants

[labrys 0]

How in the hell does my adding the missing exponential cause the 1's to suddeny cancel each other out?

Edit to add:

Yup, you're absolutly right. I had the parens in the wrong place:

1 - (1 + (interest rate / 12)) ^-N

Owned by Remi #?

[woodpecker 0]

what does the ^ symbol mean?

That is the only thing really confusing me right now.

Thanks for breaking it down for me. damn I feel dumb.

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[Mostly_Harmless 0]

^ is the exponent symbol. 2^3=2X2x2

_________________________________________
www.myspace.com/termvelocity

[woodpecker 0]

Got it and thanks to all who helped me get there. Finally pulled my head out of my ass. Even found the java input to do the "power".

Thanks again.....


Billy

SONIC WOODY #146

There is a fine line between cockiness and confidence -- which side of the line are you on?

[SkyDekker 1,465]

Its maths