Given f(x) = the quantity of x plus 7, divided by 5, solve for f-1(3).
Solution:
Given, f(x) = the quantity of x plus 7, divided by 5
We have to find f-1(3).
The fundamental operations can be performed on two or more functions to give a new function as a result.
We will use inverse of function formula to solve this problem.
f(x) = (x + 7)/5
First replace f(x) with y.
y = (x + 7)/5
Next replace x with y and y with x.
x = (y + 7)/5
Solving for y, we get,
5x = y + 7
y = 5x - 7
Finally replace y with f -1(x).
f -1(x) = 5x - 7
Put x = 3,
y = 5(3) - 7
y = 15 - 7
y = 8
Verification:
(f â f -1) (x) = x
(f â f -1) (x) = f [f-1(x)]
= f [5x - 7]
= [5x - 7 + 7]/5
= 5x/5
= x
Therefore, the inverse function when x = 3 is 8.
Given f(x) = the quantity of x plus 7, divided by 5, solve for f-1(3).
Summary:
Given f(x) = the quantity of x plus 7, divided by 5, then f-1(3) is 8.
Math worksheets and
visual curriculum
visual curriculum