9514 1404 393
Answer:
- f⁻¹(x) = 4 ±(1/3)√(-3x-18)
- y = (x -3)² +4
- y = x³/64
Step-by-step explanation:
To find the inverse function, solve for y the equation ...
x = f(y)
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1.
[tex]x=f(y)\\\\x=-3(y-4)^2-6\\\\x+6=-3(y-4)^2\qquad\text{add 6}\\\\\pm\sqrt{\dfrac{x+6}{-3}}=y-4\qquad\text{divide by -3, square root}\\\\4\pm\dfrac{1}{3}\sqrt{-3(x+6)}=y\qquad\text{add 4, rationalize the denominator}\\\\\boxed{f^{-1}(x)=4\pm\dfrac{1}{3}\sqrt{-3x-18}}\qquad\text{simplify the radical}[/tex]
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2.
[tex]x=\sqrt{y-4}+3\\\\x-3=\sqrt{y-4}\qquad\text{subtract 3}\\\\(x-3)^2=y-4\qquad\text{square both sides}\\\\\boxed{y=(x-3)^2+4}\qquad\text{add 4}[/tex]
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3.
[tex]\displaystyle x=4\sqrt[3]{y}\\\\\frac{x}{4}=\sqrt[3]{y}\\\\\left(\dfrac{x}{4}\right)^3=y\qquad\text{cube both sides}\\\\\boxed{y=\dfrac{x^3}{64}}[/tex]
