Answer
$-11,169.7^\circ$
Work Step by Step
1. Given $\vec v=-2i+j, \vec w=4i-3j$, we have $\vec v\cdot\vec w=(-2)(4)+(1)(-3)=-11$
2. We can get the angle between the vectors
$\theta=cos^{-1}(\frac{\vec v\cdot\vec w}{||\vec v || ||\vec w ||})=cos^{-1}(\frac{-11}{\sqrt {4+1}\sqrt {16+9}})\approx169.7^\circ$
