Four different mathematical models for signal processing are defined for the domain x∈Rx \in \mathbb{R}x∈R.
Which of these functions does not have an inverse function?
f(x)=12.4−0.6xf(x) = 12.4 - 0.6xf(x)=12.4−0.6x
g(x)=x3−6x2+12x+5g(x) = x^3 - 6x^2 + 12x + 5g(x)=x3−6x2+12x+5
h(x)=4sin(2x)−3h(x) = 4 \sin(2x) - 3h(x)=4sin(2x)−3
k(x)=10(1.5)xk(x) = 10(1.5)^xk(x)=10(1.5)x
