Find The Inverse Function from Tables
Questions With Solutions
Find the values of the inverse of a function given by a table? Questions are presented along with detailed Solutions and explanations.
Relationship Between a Function and its Inverse
If f is a function whose inverse is f -1, then the relationship between f and f -1 is written as:
Examples
Use the table below to find the following if possible:
a) f -1(- 4) , b) f -1(6) , c) f -1(9) , d) f -1(10) , e) f -1(-10)
a)
According to the the definition of the inverse function:
a = f -1(- 4) ⇔ - 4 = f(a) ,
Which means that a is the value of x such f(x) = - 4.
Using the table below for x = 6, f(x) = - 4. Hence a = 6 and therefore f -1(- 4) = 6
b)
a = f -1(6) ⇔ f(a) = 6
There is no value of x for which f(x) = 6 and therefore f -1(6) is undefined.
c)
a = f -1(9) ⇔ f(a) = 9
The value of x for which f(x) = 9 is equal to - 4 and therefore f -1(9) = - 4
d)
a = f -1(10) ⇔ f(a) = 10
There is no value of x for which f(x) = 10 and therefore f -1(10) is undefined.
e)
a = f -1(-10) ⇔ f(a) = - 10
The value of x for which f(x) = -10 is equal to 8 and therefore f -1(-10) = 8
More Questions with Solutions
Use the table below to find the following if possible:
1) g -1(0) , b) g -1(-10) , c) g -1(- 5) , d) g -1(-7) , e) g -1(3)
.
a)
According to the the definition of the inverse function:
Which means that a is the value of x such g(x) = 0 .
Using the table above for x = 11, g(x) = 0 . Hence a = 11 and therefore g -1(0) = 11
b)
a = g - 1(- 5) if and only if g(a) = - 5
The value of x for which g(x) = - 5 is equal to 0 and therefore g -1( - 5) = 0
c)
a = g -1(-10) if and only if g(a) = - 10
There is no value of x for which g(x) = -10 and therefore g -1(-10) is undefined.
d)
a = g -1(- 7) ⇔ g(a) = - 7
There is no value of x for which g(x) = - 7 and therefore g -1(- 7) is undefined.
e)
a = g -1(3) if and only if g(a) = 3
The value of x for which g(x) = 3 is equal to - 2 and therefore g -1(3) = - 2
More References and links
Find Inverse Function from Graph
Inverse Function
Find Inverse Function (1) - Tutorial
High School Maths (Grades 10, 11 and 12) - Free Questions and Problems With Answers
Middle School Maths (Grades 6, 7, 8, 9) - Free Questions and Problems With Answers
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