Answer:
k = 2
Step-by-step explanation:
Okay, the first thing we need to do here is find the inverse of the equation given.
f(x) = kx^3 -1
Let f(x) = m
m = kx^3 -1
m + 1 = kx^3
(m+1)/k = x^3
x = 3x√(m+1)/k
Thus, the inverse is;
f^-1(x) = 3x√(x + 1)/k
now let’s make the substitution for f^-1(15)
2 = 3x√(15+1)/k
2 = 3x√(16/k
Cube both sides
2^3 = 16/k
8 = 16/k
8k = 16
k = 16/8 = 2
