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4 votes
Show that (f o g)(x) = (g o f)(x) = x

f(x)=
(3)/(x-1)
g(x)=
(2)/(x)

1 Answer

2 votes

Answer:


- (2[1 - x])/(3) = g[f(x)] \\ \\ (3x)/(2 - x) = f[g(x)]

Explanation:

They are not.

For the g[f(x)] function, you substitute ³/ₓ ₋ ₁ from the f(x) function in for x in the g(x) function to get this:


(2)/( (3)/(x - 1))

Then, you bring x - 1 to the top while changing the expression to its conjugate [same expressions with opposite symbols]:


- (2[1 - x])/(3)

You could also do this [attaching another negative would make that positive].

For the f[g(x)] function, ²/ₓ from the g(x) function for x in the f(x) function to get this:


(3)/( (2)/(x) - 1)

Now, if you look closely, ²/ₓ is written as 2x⁻¹, and according to the Negative Exponential Rule, you bring the denominator to the numerator while ALTERING THE INTEGER SYMBOL FROM NEGATIVE TO POSITIVE:


(3x)/(2 - x)

When this happens, x leaves the two and gets attached to the three, and 1 gets an x attached to it.

I am joyous to assist you anytime.

User Tomek G
by
6.6k points
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