فهرست نشریات علمی دسترسی آزاد ایران

In the paper, we study the value distribution of the differential polynomial $\phi f^{n} f^{(k)} -1$, where $f(z)$ is a transcendental meromorphic function, $\phi(z) (\not \equiv 0)$ is a small function of $f(z)$ and $n (> 2), k (\geq 1)$ are integers. We prove an inequality which will give an upper bound for the characteristic function $T(r,f)$ in terms of reduced counting function only.