Given f(x) = the quantity of 4x plus 1, divided by 3, solve for f-1(3).
Solution:
Given, f(x) = the quantity of 4x plus 1, divided by 3
We have to find f-1(3).
f(x) = (4x + 1)/3
First replace f(x) with y.
y = (4x + 1)/3
Next replace x with y and y with x.
x = (4y + 1)/3
Solving for y, we get,
3x = 4y + 1
4y = 3x - 1
y = 3x/4 - 1/4
Finally replace y with f -1(x).
f -1(x) = 3x/4 - 1/4
Put x = 3,
y = 3(3)/4 - 1/4
y = (9 - 1)/4
y = 8/4
y = 2
Verification:
(f ∘ f -1) (x)= x
(f ∘ f -1) (x)= f [f -1(x)]
= f [3x/4 - 1/4]
= (4[3x/4 - 1/4] + 1)/3
= 3x/3
= x
Therefore, the inverse function when x = 3 is 2.
Given f(x) = the quantity of 4x plus 1, divided by 3, solve for f-1(3).
Summary:
Given f(x) = the quantity of 4x plus 1, divided by 3, then f-1(3) is 2.
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