Math (Ms. Sue Please Help)
posted by Christian on .
Determine whether the following statement makes sense or does not make sense, and explain your reasoning (modified from true/false format of text): If
f(x) = 3x, then f^1 (x) = 1/3x
A) This makes sense because the inverse would divide by 3 to "undo" the multiplication by 3 in f(x).
B) This does not make sense because although we would divide by 3 to "undo" the multiplication by 3 in f(x), the x would appear in the numerator not the denominator.

You have to be careful with the term inverse funtion.That is not the same as reciprocal.
if f(x)=3x=y
then the inverse can be found this way:
y=3x
x=3y
y=x/3 or f^1(x)=x/3
check: inverse(function)must equal x
so f^1 (f)= 3(x/3)=x so in fact it is the inverse.
So false. Go with B. When dealing with functions, the term "inverse" seldom means reciprocal. 
Please help HM

are u sure about this

Christian  Bobpursley is a math/physics/teacher. HM is probably a high school student.

Yes, Christian. But don't trust me. http://www.youtube.com/watch?v=Ec5YYVxyq44 That is the same message.