Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
3. Rational Functions and Their Graphs
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Exercise 64 Page 523

To algebraically determine the inverse of a function, switch x and y and solve for y. A function is a relation where each input is related to exactly one output.

Inverse of the Function: y=±sqrt(5x)
Result: The inverse is not a function.

Practice makes perfect
We will begin by finding the inverse of y. First, we will switch x and y and solve for y. y=x^2/5 → x=y^2/5 The resulting equation will be the inverse of the given function.
x=y^2/5
â–Ľ
Solve for y
5x=y^2
sqrt(5x)=sqrt(y^2)
sqrt(5x)=|y|

lc y ≥ 0:y = sqrt(5x) & (I) y < 0:y = - (sqrt(5x)) & (II)

ly=sqrt(5x) y=-sqrt(5x)
Now that we have found the inverse of y, we will determine if it is also a function.

Is the Inverse a Function?

A function is a relation where each input is related to exactly one output. In our case, we can see that for each x in the inverse, there are two values of y. If x=a, then y=± sqrt(5a). Therefore, the inverse of the function is not a function.