### Author Topic: Textbook error?  (Read 401 times)

#### Min Gyu Woo

• Full Member
• Posts: 29
• Karma: 12
##### Textbook error?
« on: September 14, 2018, 02:41:21 PM »
At the bottom of the page 19, it states that

Re$[(\overline{z - i\alpha})(z-s)]=0$

to show that the two segments are perpendicular.

However, on the next page it continues the proof by writing

$2$Re$[(\overline{z - i\alpha})(z-s)]=0$

Where did the $2$ come from?

#### Zhiyuan Cheng

• Newbie
• Posts: 1
• Karma: 0
##### Re: Textbook error?
« Reply #1 on: September 16, 2018, 01:31:24 PM »
They multiplied both sides by 2 so that there won't be tons of 1/2 in the calculation.