Answer:
Option B. f¯¹(x) = ³√(– x – 9)
Step-by-step explanation:
From the question given above:
f(x) = – x³ – 9
f¯¹(x) =?
We can obtain the inverse f¯¹(x) of the above equation by doing the following:
f(x) = – x³ – 9
Replace f(x) with y
y = – x³ – 9
Interchange x and y
x = – y³ – 9
Make y the subject . This is illustrated below:
x = – y³ – 9
Rearrange
x + 9 = – y³
Multiply through by –1
–(x + 9) = y³
y³ = – x – 9
Take the cube root of both side
y = ³√(– x – 9)
Replace y with f¯¹(x)
f¯¹(x) = ³√(– x – 9)
Thus, the inverse of the function
f(x) = – x³ – 9
is
f¯¹(x) = ³√(– x – 9)
