Using complete sentences, explain why f(1) = 0, f(0) = -1, and f(-1) = -2, yet f(one-third) is undefined. Be sure to show your work.
Will fan!
@mathstudent55
Is there a function that comes with this problem or do we need to make up a function?
well the first part of the question is : Simplify f(x) = the quantity 3 x-squared minus 4x plus 1 all over 3x minus 1. but idk if that goes wit it
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@mathstudent55 @Paynesdad
It does go with it.
Oh..
\( f(x) = \dfrac{3x^2 -4x+1}{3x - 1} \) L:et's find f(1): \( f(1) = \dfrac{3(1^2) -4(1)+1}{3(1) - 1} = \dfrac{3 -4+1}{3 - 1} = \dfrac{0}{2} = 0\) Ok?
okay!
You see that as the problem read, f(1) = 0. That make sense.
Yes so do I just fill in x with what ever f is ? Also how do you know if something is underfined?
Now let's calculate f(0) \(f(0) = \dfrac{3(0^2) -4(0)+1}{3(0) - 1} = \dfrac{0 -0+1}{0 - 1} = \dfrac{1}{-1} = -1\) Once again, we confirm that the given info is correct. f(0) = -1
Now we can calculate f(-1): \(f(-1) = \dfrac{3(-1)^2 -4(-1)+1}{3(-1) - 1} = \dfrac{3 +4+1}{-3 - 1} = \dfrac{8}{-4} = -2\) Once again, we have shown the given info to be true. f(-1) = -2.
Now comes the last step, to show that \(f \left( \dfrac{1}{3} \right) \) is undefined. Usually in functions, you get undefined results when they involve division by zero.
\(f(\frac{1}{3}) = \dfrac{3(\frac{1}{3})^2 -4(\frac{1}{3})+1}{3(\frac{1}{3}) - 1} \) Can you simplify the denominator? What do you get for the denominator?
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No. \( 3(\dfrac{1}{3}) - 1 = ? \) What is 3 times one-third?
oh thought it was 1/2 not 1/3 and its zero so i getttt ittt!!! THanks sooo much!
Correct. Since the denominator is zero when x = 1/3, the function is undefined at x = 1/3.
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