### Author Topic: 2.3 textbook  (Read 743 times)

#### Yan Zhou

• Full Member
• Posts: 15
• Karma: 1
##### 2.3 textbook
« on: February 09, 2020, 05:52:15 PM »
I am quite confused about the value of $2+sin\theta$. We know $sin\theta = \frac{1}{2i}(z - \frac{1}{z})$,
it says that $2 + sin\theta = 2 +(\frac{1}{2}i)(z-\frac{1}{z})$. Is that a typo?

#### Victor Ivrii

Yes, wrong sign  in the middle (should be $\drac{1}{2i}=-\dfrac{i}{2}$) but the final result is correct