What’s the inverse of the function f(x)=2x+1

Step-by-step explanation:

1.  Replace F(x) with y.

2.  Interchange x and y in  y = 2x + 1:  x = 2y + 1

3.  Solve this result for y:  2y = x - 1, or y = (x - 1)/2

4.  Replace y with:

   -1

F     (x):

   -1             x - 1

F     (x) =

                     2

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation: