Question

I keep asking for help, but so far no one has been able to help me. Please help; this assignment is due in only a couple of hours now and I can't figure this out.

Find f-1(x) (-1 is an inverse function). Sketch the graphs of y=f(x) and y=f-1(x) on the same coordinate axes. Answer for f(x)=2x+3 The answer I have is f-1(x)=x-3/2

y=2x+3
x=2y+3
x-3=2y
x/2-3/2=y

I have the answer above, but do not understand how to get the y=axes part of the graph. What part of it..

Basically, when i plug in y=2x+3, I get part of the graph, but not the other side and I do not want to get these wrong.

Answer 1

Actually the graph of f:x↦y is already the graph of f^{-1}:y↦x too. But I guess they want you to mirror it at the line {(x,y) | x=y} so that the axis are being interchanged.

Answer 2

Do you know what equations I should be entering to get the right graphs, considering they are expecting the 2

Answer 3

2x+3 and (x-3)/2 I guess.

Answer 4

what are you entering this in...graphing calculator?
you could graph it by hand

Answer 5

I can use the graphing calculator; however I am using the Algebra Program called Bagatrix - College Algebra solved which is much easier

Answer 6

ok, well you have the correct equations

Answer 7

Let me try what you have and see

Answer 8

y=2x+3 does show up properly; however nothing else I plug in works. This was just a practice question; so I have the graph to go off of, but I can't get the other equation right for some reason

Answer 9

Because calculators are set up for y= type. But like the other guy said, you are working with simple graphs, just do it by hand.