If f: R -> R is defined by f(x) = 2x – 3 and g: R -> R is defined by g(x) = x³ + 5, then (fog)⁻¹(-9) is equal to:
If f: R -> R is defined by f(x) = 2x – 3 and g: R -> R is defined by g(x) = x³ + 5, then (fog)⁻¹(-9) is equal to:
Solution
✅ Correct Option: 1
Given functions and .
First, find the composite function :
Substitute into :
Now, we need to find .
Let . By definition of inverse functions, this means .
Using the expression for we found:
Subtract 7 from both sides:
Divide by 2:
Take the cube root of both sides:
Therefore, .