f(x)=9x^3-4
Help with the steps?
2007-10-25 11:47:31 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Something to -1 means that it will be one over the number.
For example x^-1 is (1/x)
So the answer is 1/f
So to solve this...
f(x)=9x^3-4
=9X^-1
=(1/9X)
If you need more help contect me in.
rok.jhs@ gmail.com
~James
2007-10-25 11:49:31 · answer #1 · answered by =) 2 · 1⤊ 0⤋
That would mean inverse.
y = 9x^3 -4
x =9y^3 - 4
x+4 = 9y^3
(x+4)/9 = y^3
cube root ((x+4)/9) = y
Switch the x and y and solve for y. That is the inverse across the identity axis ( y=x).
2007-10-25 11:57:21 · answer #2 · answered by james w 5 · 1⤊ 0⤋
Your queation is to find f^-1, that means f^-1(x):
Let say, f(x) = y
Then, f^-1(y) = x
So, y = 9x^3-4
y+4 = 9x^3
(y+4)/9 = x^3
3^√((y+4)/9) = x
Next, we know that f^-1(y) = x
So, f^-1(y) = 3^√((y+4)/9)
Lastly, f^-1(x) = 3^√((x+4)/9)
2007-10-25 12:05:49 · answer #3 · answered by Nizam89 3 · 0⤊ 0⤋
f^-x = 1/f^x
2007-10-25 11:51:15 · answer #4 · answered by Steve M 2 · 0⤊ 0⤋
well you start with y=9x^3-4 ...
then replace the y with x and the x with y...
so you get x=9y^3-4
and then all you have to do is solve for y and that's your
f^-1
2007-10-25 11:52:00 · answer #5 · answered by Anonymous · 0⤊ 0⤋
No. It is not 1/f. Replace x with f and f with x.
x = 9f^3 - 4
1/9(x + 4) = f^3
f(x) = cube root((1/9)(x + 4))
2007-10-25 11:50:59 · answer #6 · answered by Chase 3 · 0⤊ 0⤋
substitute in -1 for x, so
f (-1) = 9(-1)^3 -4
you should be able to take it from there. -1 cubed is -1.
2007-10-25 11:52:20 · answer #7 · answered by Judy 7 · 0⤊ 0⤋