please help with f(x) = (x-4)^3-4(x-4)

Jodene222

Junior Member
Joined
Aug 1, 2007
Messages
51
please HELP
f(x) = (x-4)^3-4(x-4)

This is how far I got.

x^3-8x^2+40x-48=0

THANKS
 
Directions

Directions:
Find all zeros of f. Identify al multiple zeros.

The answers are 2,4,6
 
\(\displaystyle \begin{array}{rcl}
\left( {x - 4} \right)^3 - 4\left( {x - 4} \right) & = & \left( {x - 4} \right)\left[ {\left( {x - 4} \right)^2 - 4} \right] \\
& = & \left( {x - 4} \right)\left( {x^2 - 8x + 12} \right) \\
\end{array}\)

Can you finish?
 
I'll do a similar poblem for you.

Find all the zero's of

f(x) = A*(x-b)^3 - C*(x-b)

= (x-b) * [A*(x-b)^2 - C]

Now further factorize the expression within [] - it is a quadraticand easy to factorize.

Then use the definition of "zeros of function" to indicate the zeros.
 
help factoring

x^3-8x^2+40x-48 = 0
I am sure this is correct so far. I don't know how to factor this polynomial so I can solve for 0

I need help factoring these four terms.
thanks
 
You dont need to expand the cubic equation!!!

Look at the solutions and hints provided above - carefully
 
please HELP

I don't know how you did this. However, I was able to solve the problem and get the right answers, but do not fully understand this formula. It seems like I am missing 1 (x-b)

f(x) = A*(x-b)^3 - C*(x-b)

= (x-b) * [A*(x-b)^2 - C]
 
pka said:
\(\displaystyle \begin{array}{rcl}
\left( {x - 4} \right)^3 - 4\left( {x - 4} \right) & = & \left( {x - 4} \right)\left[ {\left( {x - 4} \right)^2 - 4} \right] \\
& = & \left( {x - 4} \right)\left( {x^2 - 8x + 12} \right) \\
\end{array}\)

Can you finish?

Did you even look at this post?
 
thanks

Thanks, I understand now. (x-1) was factored out.
Thanks again for your patience!
Jodie
 
Re: thanks

Jodene222 said:
Thanks, I understand now. (x-1) was factored out.

No.....

(x - 4) was factored out


Thanks again for your patience!
Jodie
 
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