Find a parametric equation to solve a line integral Find 
$ \int_C \frac{dz}{z} $ from $1 - 5i$ to $5 + 6i$
I want to use 
$$\int_C f(Z) dz = \int_a^b f[z(t)]z'(t)dt$$
My guess is that I need to find $z(t)$ such that 
$$z(a) = 1 - 5i$$
$$z(b) = 5 + 6i$$
But how?

Hint : 
$$z(t)=(b-a)t+a$$ $$  t\in [0,1]$$
So $$z(0)=a$$
$$z(1)=b$$
