Assume f is a one-to-one function

[the_slow1]

I didn't know how I should go about solving this problem, could you give me an ideal so I can solve the problem?

the problem reads:


Assume f is a one-to-one function

If f(5)=18, find f^-1(7) AND If f^-1(4)=2, find f(2)

 

[Guest]

if it is a one to one function then it will have an equation like this
y=x +c where c is any number


f(5)=18, find f^-1(7)

18 = 5+c
c=13

y=x+13


f^-1(7) ==== 1/(x+13)
= 1/(7+13)
= 1/20

 

[Gene]

Are you sure of the problem? The part after AND is easy. It is one-to-one so if the inverse of 4 is 2 then f(2)=4
If it is all one problem then it is y = ax+b and
a*5+b=18
a*2+b=4
can be solved for a & b but a & b are not neat.