Property of Modified Bessel function of first kind

Question

While reading a scientific paper, I have come across a property of modified Bessel function: $$\frac{I_1(az)}{I_0(az)}=\frac{1}{a}\frac{I_1(z)}{I_0(z)}$$ Is this property true? If not, how can the LHS be written in terms of $I_1(z)$ and $I_0(z)$?

Answer 1

This property is not true.

Graph from Wolfram Alpha.