SOLUTION: Analytically show that the function f(x)=10-∛(x-8)
is one-to-one, find its inverse, and evaluate the following:
f^(-1) (10)
f^(-1) (11)
f^(-1) (12)
Algebra.Com
Question 1125606: Analytically show that the function f(x)=10-∛(x-8)
is one-to-one, find its inverse, and evaluate the following:
f^(-1) (10)
f^(-1) (11)
f^(-1) (12)
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
If f(x) is one-to-one, then implies that for all a,b in the domain of f(x). Put in plain english: if two output values are the same, then the inputs must be the same for the function to be one-to-one.
Consider a counter-example such as a parabola. We can have the same output lead to two different inputs (eg: y = 4 lead to x = -2 and x = 2 for the function y = x^2). This is a reason why a parabola is not one-to-one.
--------------------------------------------
If , then...
Substitution
Subtract 10 from both sides
Multiply both sides by -1
Cube both sides
Add 8 to each side
So we end up with after assuming
So this means that leads to . If we follow the steps shown above in reverse, then we'll go from to
Therefore, we have proven that f(x) is indeed one-to-one.
--------------------------------------------
Let's find the inverse. Which I'll call g(x)
g(x) = f^(-1)(x)
Replace f(x) with y
Swap x and y. From here on out, we're solving for y.
Subtract 10 from both sides
Multiply both sides by -1
Cube both sides
Add 8 to both sides
The inverse is
--------------------------------------------
Let's use the inverse to compute the inputs x = 10, x = 11, x = 12
------
------
RELATED QUESTIONS
1.Analytically show that the function is one-to-one, find its inverse, and evaluate the... (answered by MathLover1)
Show that the given function is one-to-one and find its inverse. Check your answers... (answered by CubeyThePenguin)
The function f is one-to-one. Find its inverse.
f(x) = (x -... (answered by stanbon)
3. The following function is one-to-one. Find its inverse. Find the domain and range of f (answered by stanbon)
Use the defination of inverse function to show analytically that f and g are inverse:... (answered by funmath)
The function f is one-to-one, find its inverse and determine the domain and range of both (answered by stanbon)
the function f is one to one. Find its inverse... (answered by stanbon,katealdridge)
For a one-to-one function f(x) and its inverse function f^-1(x), the domain of f(x) is... (answered by Fombitz)
The following function is one to one. Find the inverse of the function and graph the... (answered by robertb)