214k views
5 votes
Given f(x) = 2x³, explicitly find the inverse function and use it to determine the value of f⁻¹(16). (Recall that the cube root of a can be written as a⅓).

User Zlatomir
by
8.4k points

1 Answer

7 votes

Final answer:

The inverse function of f(x) = 2x³ is f⁻¹(x) = (x/2)⅐. To find f⁻¹(16), we plug in 16 and solve, resulting in f⁻¹(16) being equal to 2.

Step-by-step explanation:

To find the inverse function of f(x) = 2x³, we need to swap the roles of x and y and solve for y:

  1. Start with y = 2x³.
  2. Rewrite it as x = 2y³ to swap x and y.
  3. Divide both sides by 2, getting x/2 = y³.
  4. Take the cube root of both sides to solve for y, giving us y = √(x/2) or y = (x/2)⅐.

So the inverse function is f⁻¹(x) = (x/2)⅐.

To find f⁻¹(16), we substitute 16 into the inverse function:

  1. f⁻¹(16) = (16/2)⅐
  2. f⁻¹(16) = (8)⅐
  3. f⁻¹(16) = √8 or ¹²

The value of f⁻¹(16) is ¹² or 2.

User Pcoates
by
8.0k points