Problem 1
Answer: You are correct. They are inverses
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Explanation:
One way to see if we have an inverse pair or not is to compute these two composite functions
If both result in x, and just that, then we have shown that they are inverses of one another.
f(x) = (2x)/3
f(x) = (2/3)x
f(g(x)) = (2/3)*g(x)
f(g(x)) = (2/3)*(3/2)x
f(g(x)) = x
The steps to show that g(f(x)) = x are very similar
g(x) = (3/2)x
g(f(x)) = (3/2)*f(x)
g(f(x)) = (3/2)*(2/3)*x
g(f(x)) = x
So this verifies that you have the correct answer.
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Problem 2
Answer: These functions are inverses of each other.
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Explanation:
We'll use the same idea as problem 1
f(x) = 2 - (3/4)*x
f(g(x)) = 2 - (3/4)*( g(x) )
f(g(x)) = 2 - (3/4)*( (-4/3)x + 8/3 )
f(g(x)) = 2 - (3/4)*(-4/3)x - (3/4)*(8/3)
f(g(x)) = 2 + x - 2
f(g(x)) = x
So far so good, but we need to check the other way around as well
g(x) = (-4/3)x + 8/3
g(f(x)) = (-4/3)*( f(x) ) + 8/3
g(f(x)) = (-4/3)*( 2 - (3/4)*x ) + 8/3
g(f(x)) = (-4/3)*(2) + (-4/3)*(-3/4)*x + 8/3
g(f(x)) = -8/3 + x + 8/3
g(f(x)) = x
This verifies that f(x) and g(x) are inverses of each other.
Problems 3 and 4 will have similar steps.
