Q. For the function f(x)=9−2x3, find f−1(x).Answer: f−1(x)=
Replace with y: To find the inverse function, f−1(x), we need to switch the roles of x and y in the original function and then solve for y. Let's start by replacing f(x) with y for clarity.y=9−2x3
Switch x and y: Now, switch x and y to find the inverse function.x=9−2y3
Cross-multiply to eliminate fraction: Next, we solve for y. To do this, we'll first cross-multiply to get rid of the fraction.x×(9−2y)=3
Distribute x: Distribute x into the parentheses.9x−2xy=3
Isolate term with y: We want to isolate the term with y, so let's move the term without y to the other side by subtracting 9x from both sides.−2xy=3−9x
Divide by −2x: Now, divide both sides by −2x to solve for y.y=−2x3−9x
Factor out −3: We can simplify the expression by factoring out a −3 from the numerator.y=−2x−3(1+3x)
Cancel negative signs: The negative signs in the numerator and denominator cancel each other out.y=2x3(1+3x)
Write inverse function: Finally, we can write the inverse function by replacing y with f−1(x).f−1(x)=2x3(1+3x)
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