Finding the Inverse of a Function: g(x) = x/3 - 5

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The inverse of the function g(x) = x/3 - 5 is correctly calculated as g^-1(x) = 3x + 15. To verify the correctness of the inverse, one can graph both functions, noting that the inverse should appear as a 90-degree rotation of the original. Additionally, forming a composite function of g(x) and its inverse confirms the result, as g[g^-1(x)] simplifies back to x. The discussion concludes that the inverse found is indeed accurate.
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Homework Statement



Inverse of g(x) = x/3 -5


Homework Equations





The Attempt at a Solution



The inverse of the function

g(x) = x/3 -5
x= y/3 -5
x +5 = y/ 3
3x + 15 = y

Is this correct?

Or is it x+5 /3 ?
 
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Your original looks correct.

If you have a graphic calculator, graph them both, the inverse should be a 90* rotation from the original, since you essentially have the same function with swapped axis.
 
If you want to check to see if the inverse function you found is correct, all you need to do is form a composite function of the original function and its inverse. If the composite function of g(x) and g-1(x) is equal to x, then the inverse you found is correct.

g[g^{-1}(x)]=(\frac{3x+15}{3})-5=(x+5)-5=x

Yes, the inverse you found is correct.
 
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