help me with this algebra please.
 

i'm stumped. help me find X

A=B(1+X)^n

I've been trying to figure it out for the past hour. It is basically the time value of money equation. the unknown is the rate (X)
A=new value
B=old value
n=# of periods

Dear Algebra,

I don't know where your X is, nor do I care Y they haven't come back.

Yours truly,

Me

man, that is profound! :D

can you do

take the nth root of (a/b) -1 = x

??

its been a while for me too.

LOL

This would be a problem I'd have my daughter look at later tonight to see if it makes sense to her. She's in advanced Algebra II at her high school.

I'll let you know what she comes up with...

no. i tried that. i suspect that both sides have to be raised to the "e". just not sure.

That's what I got also.

that's gotta be it. i just could not use the calculator properly. thanks guys. you rock

nope. it will take an algebra genius to get this right.

if A=121, B=100, n=2 then X=10%

i can use a HP 12c financial calculator but I can't figure out the algebra part

If you plug those numbers into the equation TheDon offered, doesn't it work for you? It does for me.

Most TI calculators you can enter direct and it scrambles the eggs for you and pops out the answer.

Just quickly, since I hate these problems.

EDIT: nevermind, I got it... x=(a/b)^(1/n)-1

pure genius. that is it!!!!

please show me how you did it.

If you have Excel on your computer, you can simply type any formula you want into the cells and then plug values in and it will do the calculations for you.

fyi, there is now an iphone app for the HP12c. It's about 3 bucks my partner told me. He uses it all the time;)
(I still use the 19B "booklet" It works!:cool:)

Does anyone sit down with pen and paper anymore? I used to use trig on a daily basis, and rarely used a calculator. My kids are issued calculators in school. Heck, most of the most common sines used, I memorized years ago.

I guess it is one of those things that you lose if it isn't used.

Pen & Paper? No. Only to take notes. Number crunching is why computers were invented. That and doing your tax returns :P;)
Think of the ctizen revolt if people had to try and navigate their returns today with pencil and paper. Want a simple tax code? Ban computer use. Won't happen you say? Neither will the tax code become "simple"
If I could relive my yute and could choose between becoming proficient in math or the piano, I'd choose the piano. My mother gave up wasting money on me taking piano lessons.:o

I'm always sketching and figuring on paper. It seems like it's much easier to be creative on the spur of the moment if you're not near a computer or other electronic device.

I also do all of my initial sketching on paper for projects. I'm pretty decent at drawing to scale and after the concept is laid out, I move to the computer for actual scale drawings.

Over here they now have maths exams that are tech free. They make the students use their brain & show that they actually understand how to do maths.
A well trained monkey can push buttons on a calculator.

Log(A) = B+ n log(1+x)
Log(A)-B = n(log(1+x)
(Log(A)-B)/n = log(1+x)
exp((Log(a)-b))/n) = exp(log(1+x))
exp(A-B)-exp(n) =1+x
x = exp(A-B)-exp(n) -1

Is that right?

Trig is easy to do on paper as long as you have CRC tables. Without them it is much more time consuming. A scientific calculator makes it a walk in the park.

Oscar Has A Heap Of Apples

I used a pen and paper, lol. Apparently I Was wrong but I'd like to see the math behind it as well to see where I messed up

I hated algebra but I need to take Calc 1 just for fun so I have it on my transcripts

okay.

A=B(1+X)**(n)

A/B=(1+X)**(n)

ln--> natural log

ln(A/B)=(n) ln(1+X)

(1/n) ln(A/B)=ln(1+x)

(1/n) ln(A/B)=ln(1)+ln(X)

(1/n) ln(A/B) - ln(1)= ln(x)

e**[(1/n) ln(A/B)]-e**[ ln(1)] = e**[ln(X)]

(A/B)**(1/n) -1= X