Pearson Algebra 2 Common Core, 2011
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Pearson Algebra 2 Common Core, 2011 View details
2. Properties of Exponential Functions
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Exercise 62 Page 450

To determine the inverse of f(x), first replace f(x) with y. Then switch x and y and solve for y.

Inverse: f^(- 1)(x)=sqrt(x-1/5)
Is the inverse a function? Yes.

Practice makes perfect

To find the inverse of f(x), we will replace f(x) with y. f(x)=5x^3+1 → y=5x^3+1 Next step is to switch x and y in the function rule. y=5 x^3+1 → x=5 y^3+1 Now we need to solve for y. The resulting equation will be the inverse of the given function.

x=5y^3+1
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Solve for y
x-1=5y^3+1-1
x-1=5y^3
x-1/5=5y^3/5
x-1/5=y^3/1
x-1/5=y^3
sqrt(x-1/5)=sqrt(y^3)
sqrt(x-1/5)=y
y=sqrt(x-1/5)

Finally, to indicate that this is the inverse function of f(x), we will replace y with f^(- 1)(x). y=sqrt(x-1/5) → f^(- 1)(x)=sqrt(x-1/5) A function is a relation where each input is related to exactly one output. In this case, for each x there is only one value of y. Therefore, f^(- 1)(x) is a function.