To remodel a bathroom a contractor Charles $25 er hour plus material costs, which amount to $3825. Therefore, the total cost to remodel he bathroom is given by f(x)=25x+3825 where x is the number of hours the contractor works. Find a formula for f^-1(x). What does f^-1 compute?

Question

To remodel a bathroom a contractor Charles $25 er hour plus material costs, which amount to $3825.  Therefore, the total cost to remodel he bathroom is given by f(x)=25x+3825 where x is the number of hours the contractor works.  Find a formula for f^-1(x). What does f^-1 compute?

Thanks for your help:-)

Anonymous · Answer

Switch the variables x and y

y=25x+3825 would become

x=25y+3825 (solve for y)

x-3825=25y

y=(x-3825)/25

and if you do f(-fx) meaning you plug in the inverse into the x of the original function, you should get x.