Inverse Function Example 6 (Comparison Method)


Example 6 (Comparison Method)
If f:xmxnx2,x2   and f1:x52x2x,x2. . Find the value of m and of n,


Inverse Function Example 5

Example 5

If g:xmxx3,x3 and g1(5)=14. Find the value of m.

 

Inverse Function Example 3


Example 3
Find the inverse function of f(x)=3x+25x+3


Inverse Function Example 2


Example 2
Find the inverse function of the following function
(a) f(x)=57x
(b) f(x)=23x


Inverse Function Example 1


Example 1
Find the inverse function of the following function
(a) f(x) = 4 – 7x,
(b) f(x)=2x+53


1.4 Inverse Function

Inverse  Functions

1. Consider the function (f : x maps to  - 2) with domain A = {1, 3, 4, 7}. Then the range of the function is B = {-1, 1, 2, 5}. The arrow diagram representing this function is shown as below.


2. If the arrows of (a) are reversed, the arrow diagram in (b) is obtained. A new function having domain B and range A is formed from the function f.  This new function is called the inverse function of f and is denoted by  f-1 .


3. To Find the inverse function, f1(x) of f(x)
Put the function equal to y.
Rearrange to give x in term of y.
Rewrite as f1(x)  replacing y by x.

Example: Given f(x)=5x4   , find the inverse function.



 


   

Finding a new function given a composite function (Case B : Second function is given) Example 3

Example 3 (Substitution Method)
A function f is defined by f:x7x  .
Find the function g if gf:x102x+3,x32  .

[Note : Second function is given, use substitution method] 



Finding a new function given a composite function (Case B : Second function is given) Example 2


Example 2 (Substitution Method)
A function f is defined by f:xx1  .
Find the function g if gf:x4x+2,x2  .

[Note : Second function is given , use substitution y = x - 1]





Finding a new function given a composite function (Case B : Second function is given) Example 1


Example 1 (substitution Method)
A function f is defined by f:xx+2  .
Find the function g if gf:xx2+3x+5  .

[Note : Second function is given, use substitution y = x + 2]



Finding a new function given a composite function (Case A : First function is given) Example 3


Example 3
A function f is defined by f:x2x+1  .
Find the function g if fg:x5x2x+5,x5  .

[Note : First function is given]

Click here (check for example 5)