Trigonometric-Identity Problem (Quick Question)

[MIIF]

Shouldn't the quadrant in the orange circle (or whatever it looks like) match with the quadrant in the green one (i.e., Quadrant I)? Thanks.https://uploads.tapatalk-cdn.com/20180601/f3bb14bdcd0ee44fbf84ed81cf266d40.jpghttps://uploads.tapatalk-cdn.com/20180601/aa252ceb0ebb22a7848051a85b6a9a29.jpg

 

[Olinguito]

Yes, it looks like a typo. However the answers are the same whether $B$ is in QI or QIII.

 

[MIIF]

Yes, it looks like a typo. However the answers are the same whether $B$ is in QI or QIII.

Yes, perhaps that's the case, but wouldn't the answers be different considering the quadrant difference (e.g., the sign switch for the answer in (a))?https://uploads.tapatalk-cdn.com/20180601/a861c1250b3bd26b068231593e477c43.jpghttps://uploads.tapatalk-cdn.com/20180601/a09baa55d2efcec59dbda1570322f355.jpg