Solve this equation and win a prize! (I screwed up the equation!! .. correct one inside!!!)

[LordJezo]

It's not for class or anything.. just trying to test the power of computers, and I cant find one that will solve it:


48*x*(1+x)^60 - (1+x)^60 + 1= 0


Anyone?

ack.. I goofed the equation. The corrected version is above

 

[cjchaps]

x = -1
?

 

[iamwiz82]

x = -1

 

[Pundit]

<< x = -1 >>



or x = 1/48 if I read the question correctly.

 

[LordJezo]

<< or x = 1/48 if I read the question correctly. >>



That one dosent seem to work..

 

[Czar]

My Sharp EL-5120 calculator gives me x=-0.02083333333333333333333

 

[Ns1]

<< 48*x*(1+x)^60 - (1+x)^60 = 0 >>




so the equation was

48x((1+x)^60) - ((1+x)^60) = 0


right?

then yeah, -1 ^_^

 

[b0mbrman]

(48x)(1+x)^60 - (1+x)^60 = 0
(48x-1)(1+x)^60 = 0
(48x-1) = 0 or (1+x)^60 = 0
x = 1/48 or x = -1

 

[b0mbrman]

<<

<< or x = 1/48 if I read the question correctly. >>



That one dosent seem to work.. >>


48*x*(1+x)^60 - (1+x)^60 = 0

let h = (1+x)^60
let x = 1/48

48*(1/48)*h - h = 0
(1)*h - h = 0
h - h = 0
0 = 0

 

[RSMemphis]

<<

<< x = -1 >>



or x = 1/48 if I read the question correctly. >>



Yeah, that's the second solution.

Proof:

(48x - 1)(x + 1)^60 = 0

If either of the expressions within () is zero, the whole thing is zero.

Thus 1/48 and -1 are the two solutions to the problem.

Ah, someone beat me to it... D'oh

 

[RSMemphis]

<< My Sharp EL-5120 calculator gives me x=-0.02083333333333333333333 >>


That's 1/48

 

[LordJezo]

I screwed up the equation.. new one is above!

Forgot the + 1 at the end

 

[AkumaX]

<<

<< My Sharp EL-5120 calculator gives me x=-0.02083333333333333333333 >>


That's 1/48 >>




haheahehahhaeh

 

[Capn]

x = 0

 

[Viper GTS]

My TI-92+ could do it in it's sleep.

Unfortunately I don't have it here & I'm too lazy to solve it by hand.

Viper GTS

 

[LordJezo]

<< My TI-92+ could do it in it's sleep.

Unfortunately I don't have it here & I'm too lazy to solve it by hand.

Viper GTS >>



Oh well... my 89 has been working on it for a few hours now. I am going to give up on it soon

 

[MereMortal]

x=0, -1.9271561199907937 (sign reversal) , 0.007628602809953785

 

[dullard]

<< just trying to test the power of computers >>


Do you have access to a spreadsheet? Most OEM computers have some form of spreadsheet that comes installed. Or you can download one quickly.

Type your equation into the spreadsheet. Hit solve. Wait 0.01 seconds. Get your answer.

If that isn't the answer you wanted, give it a different initial guess. Hit solve. Wait 0.01 seconds. Get your answer.

Sure there are better methods. However, this one is easiliy available to most computer users.

Edit: the nice thing about this method it that you can easily solve for multiple variables at the same time. Many graphic calculators don't have that capability built in. Yes you can program it, but you could just as easily program your computer to do the same thing...

 

[notfred]

looks like -1 works. I didn't even need a calculator (1-1)^60 is 0. 0-0+1... it's easy from there.

 

[TuffGirl]

<< looks like -1 works. I didn't even need a calculator (1-1)^60 is 0. 0-0+1... it's easy from there. >>

What?? 0-0+1 != 0

 

[Viper GTS]

<<

<< My TI-92+ could do it in it's sleep.

Unfortunately I don't have it here & I'm too lazy to solve it by hand.

Viper GTS >>



Oh well... my 89 has been working on it for a few hours now. I am going to give up on it soon >>



Your 89 has taken that long?

What command did you use?

I would use:

solve(48*x*(1+x)^60 - (1+x)^60 + 1= 0,x)

Viper GTS

 

[TuffGirl]

Hey what is the prize anyway??? I'm surprised noone has asked yet.

LordJezo, I'm sure you can easily solve it using Maple. I'm pretty sure that's on Eden.

 

[spanky]

the answer is "B"

 

[notfred]

<<

<< looks like -1 works. I didn't even need a calculator (1-1)^60 is 0. 0-0+1... it's easy from there. >>

What?? 0-0+1 != 0 >>




hmm, you're right, I'm dumb.

 

[notfred]

solve(48*x*(1+x)^60 - (1+x)^60 + 1= 0,x) <- my TI-89 is doing that exact thing right now.... been going for a minute or two so far.