# Complex variables, maximum value

2. Homework Equations
Let $$w \in C$$ be a fixed complex number with $$|w|<1$$. Let
$$f(z)=\frac{z-w}{1-\bar{w}z}.$$
Calculate its maximum value in the region $$|z| \leq 1$$.

3. The Attempt at a Solution
How should I approach this? Not sure if maximum modulus principle is of much help.