Question 639432
A)  f(x)=x²
B)  f(x)=x³
C)  f(x)=x
<pre>
In each case replace f(x) by y

A)  y = x²
B)  y = x³
C)  y = x

Interchange the variables x and y

A)  x = y²
B)  x = y³
C)  x = y

For each, ask the question "Is this equivalent to what it was before the variables were interchanged?

A)  Is x = y² equivalent to y = x²?  Answer: NO
B)  Is x = y³ equivalent to y = x³?  Answer: NO
C)  Is x = y  equivalent to y = x ?  Answer: YES

So the answer is C)  f(x)=x

Edwin</pre>