Math homework

Question

If point (a,b) lies on the graph y=f(X), the graph y=f^-1(X) must contain point ....

A.(b,a)

B.(a,0)

C.(0,b)

D.(-a,-b)

Answer 1

If (a,b) lies on the graph y=f(x), then

                       f(a)=b

 

So,

         f^-1(b)=a

Which means (b,a) lies on f^-1(x).

 

Therefore, the correct answer is (b,a).