2(x-1)^3=x+1

- anonymous

2(x-1)^3=x+1

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- chestercat

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- lgbasallote

hmm okay?

- anonymous

can u solve it?

- anonymous

???

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## More answers

- lgbasallote

solve for x?

- anonymous

yeah

- lgbasallote

here's my thought
let x - 1 = a
therefore a +1 = x
2a^3 = a + 1 + 1
2a^3 = a + 2
2a^3 - a - 2 = 0
does that give you any ideas?

- anonymous

2(x-1)^3=x+1 noo sorry not really can u tell me how to do it just by factoring etc?

- lgbasallote

lol that's what im thinking too

- lgbasallote

@myininaya pls help here

- myininaya

Hey @lgbasallote what was wrong with your way?

- myininaya

It seems to be awesome! :)

- lgbasallote

i don't know what to do next lol

- myininaya

Try doing a little of testing possible rational zeros for what you have

- myininaya

Synthetic division will come in handy

- lgbasallote

you heard her @louis413 ;)

- anonymous

lol im only in alg/trig in high schooll.. loll wut is that?

- myininaya

oh wait i think i made a mistake anyways...
let me try again
but yeah that is what i would do test to see if any possible rational zeros work

- myininaya

algebra/trig?
which one?

- anonymous

well im takling the algebra2/trig course right now at summer school

- myininaya

synthetic division and looking at possible rational zeros are in algebra

- myininaya

ok so what have you learned then?

- anonymous

factoring... quadratic formula completeing the squares etc

- myininaya

And is your equation written correctly?

- anonymous

yes can it be solved like 2(x-1)^2(x-1)-1(X-1)=0

- myininaya

I can only see to find a real approximation by looking at the graph and seeing where it crosses the x-axis

- shubhamsrg

would you like to go for a trignometric solution?
might seem complicated but is easy..
involves inverse function just a bit..and sin 3x etc formullas ?

- shubhamsrg

well..
in 2a^3 - a - 2 = 0
let a = m sin y
=> 2m^3 sin^3 y - msin y -2 =0
multiplying both sides by (-2/m^3)
=> -4sin^3 y + 2sin y/(m^2) + 4/(m^3) =0
our aim is to convert this in the form of
-4sin^3 y + 3 siny which will convert it into sin 3y and simplify things
we have to chose a particular value of m for that purpose
in our case
2/m^2 = 3
or m = sqrt(3/2) and -sqrt(3/2)
thus we have these 2 eqns :
-4sin^3 y + 3sin y + 8sqrt(2)/(3sqrt(3)) = 0
and
-4sin^3 y + 3sin y - 8sqrt(2)/(3sqrt(3)) = 0
=> sin 3y = - 8sqrt(2)/(3sqrt(3))
and
=>sin 3y = 8sqrt(2)/(3sqrt(3))
now using any scientific calculator, we may find value of y,then a(=msin y)
and then finally x(=a+1)

- shubhamsrg

hope i was able to explain well..

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