Questions: Find the inverse of the function f(x)=-3x^2.
Transcript text: Find the inverse of the function $f(x)=-3 x^{2}$.
Solution
Solution Steps
To find the inverse of the function \( f(x) = -3x^2 \), we need to follow these steps:
Replace \( f(x) \) with \( y \).
Swap \( x \) and \( y \).
Solve for \( y \) in terms of \( x \).
Replace \( y \) with \( f^{-1}(x) \).
Step 1: Define the Function
We start with the function given by \( f(x) = -3x^2 \).
Step 2: Replace \( f(x) \) with \( y \)
We set \( y = -3x^2 \).
Step 3: Swap \( x \) and \( y \)
Next, we swap the variables to get \( x = -3y^2 \).
Step 4: Solve for \( y \)
To find the inverse, we solve for \( y \):
\[
-3y^2 = x \implies y^2 = -\frac{x}{3} \implies y = \pm \sqrt{-\frac{x}{3}}
\]
However, since the original function \( f(x) = -3x^2 \) is not one-to-one over all real numbers, we restrict the domain to \( x \leq 0 \) to ensure the inverse is a function. Thus, we take the negative root:
\[
y = -\sqrt{-\frac{x}{3}}
\]
Final Answer
The inverse function is given by:
\[
\boxed{f^{-1}(x) = -\sqrt{-\frac{x}{3}}}
\]