# Toronto Math Forum

## MAT334--2020S => MAT334--Lectures & Home Assignments => Chapter 2 => Topic started by: Yan Zhou on February 09, 2020, 05:52:15 PM

Title: 2.3 textbook
Post by: Yan Zhou 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?
Title: Re: 2.3 textbook
Post by: Victor Ivrii on February 09, 2020, 06:54:26 PM
Yes, wrong sign  in the middle (should be $\drac{1}{2i}=-\dfrac{i}{2}$) but the final result is correct