Question 56072
Given f(x)=3x+4 
1. Is f(x) a function? Why or why not? 
Yes, it is a function because for each value of "x"
there is only one value of "y"---the y will be 3 times
the x value plus 4.
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2. Is f -1(x) a function? Why or why not? 
Yes it is.  The inverse function can be found as follows:
y=3x+4
Interchange x and y to get:
x=3y+4
Solve for y to get:
y=(1/3)x-(4/3)
This is a function for the same reasons given
in part #1.
Cheers,
Stan H.