Question 8.18: Prove that for closed polygons, the sum of the exponents (a1...

Prove that for closed polygons, the sum of the exponents \left(\alpha_{1} / \pi\right)-1,\left(\alpha_{2} / \pi\right)-1, \ldots,\left(\alpha_{n} / \pi\right)-1 in the Schwarz-Christoffel transformation (8.9) or (8.10), page 247 , is equal to -2 .

{\frac{d w}{d z}}=A(z-x_{1})^{\alpha_{1}/\pi-1}(z-x_{2})^{\alpha_{2}/\pi-1}\cdot\cdot\cdot(z-x_{n})^{\alpha_{n}/\pi-1}             (8.9)

w=A\int(z-x_{1})^{\alpha_{1}/\pi-1}(z-x_{2})^{\alpha_{2}/\pi-1}\cdot\cdot\cdot(z-x_{n})^{\alpha_{n}/\pi-1}d z+B                  (8.10)

The blue check mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

The sum of the exterior angles of any closed polygon is 2 \pi. Then

\left(\pi-\alpha_{1}\right)+\left(\pi-\alpha_{2}\right)+\cdots+\left(\pi-\alpha_{n}\right)=2 \pi

and dividing by -\pi, we obtain as required,

\left(\frac{\alpha_{1}}{\pi}-1\right)+\left(\frac{\alpha_{2}}{\pi}-1\right)+\cdots+\left(\frac{\alpha_{n}}{\pi}-1\right)=-2

Related Answered Questions

Question: 8.23

Verified Answer:

A set of parametric equations for the ellipse is g...
Question: 8.17

Verified Answer:

We must show that the mapping function obtained fr...
Question: 8.26

Verified Answer:

It suffices to prove that the transformation maps ...