Write Function Swap: Write down the function and swap x and y to begin finding the inverse.We have f(x)=x2−5 for x≤0. To find the inverse, we replace f(x) with y and then swap x and y to solve for the new y.y=x2−5 becomes y0.
Solve for Inverse: Solve for y to find the inverse function.We need to isolate y on one side of the equation. Start by adding 5 to both sides of the equation.x+5=y2.
Square Root Solve: Take the square root of both sides to solve for y.Since we are looking for the inverse function where the original function is defined for x≤0, we need to take the negative square root because the output of the original function is non-positive when x is non-positive.y=−x+5.
Replace with Notation: Replace y with the inverse notation.The inverse function is denoted as f−1(x), so we replace y with this notation.f−1(x)=−x+5.
State Domain: State the domain of the inverse function.The domain of the inverse function is the range of the original function. Since the original function is defined for x≤0 and is a downward-opening parabola (because we only consider x≤0), the range is all y≤6 (the y-coordinate of the vertex of the parabola). Therefore, the domain of the inverse function is x≤6.
More problems from Find the vertex of the transformed function