Question

Which of the following pairs of functions are inverses of each other?

Answer 1

A. f(x)=9(2/×)-4 and g(x)=(x/18)+4
B. f(x)=9(x/2)-8 and g(x)=2(x+8)/9
C. f(x)=8(x-3)+4 and g(x)=(x+3/8)-4
D. f(x)=(x-7/9)+10 and g(x)=9(x+7)-10

Answer 2

@luffingsails

Answer 3

Please help!

Answer 4

I'll give you the method...
Take f(x) = 9(2/x) - 4
Solve it for x:
f(x) + 4 = 9(2/x)
x(f(x) + 4) = 9 * 2
x = (9 * 2) / ( f(x) + 4 )
inverse f(x) = (9 * 2) / ( f(x) + 4 )

Answer 5

You would just need to check each f(x) in the same manner and see which g(x) is the inverse produced in those steps.

Answer 6

Ok but how can i tell which one is an inverse?

Answer 7

if you have given a function in terms of x , like y=f(x)
For writing inverse of that function,you have to do is write a function in terms of y like x=f(y)

Example :-
y=3x+2
To write its inverse,we have to write a function in terms of y,
so subtract 2 from both the sides,
y-2=3x
then divide 3 on both the sides,we get
x=y-2/3<---inverse of given function

Answer 8

Hello @Lilah , you've posted in the OpenStudy Feedback group which is for feedbacks and suggestions for OpenStudy only, there is a group specifically for Maths questions right here:

http://openstudy.com/study#/groups/Mathematics