# trig problem involving double angle forumlas

• Oct 21st 2012, 07:37 PM
kingsolomonsgrave
trig problem involving double angle forumlas
Attachment 25325

in the problem in the above picture, how did they get from $2cox+2sinxcox=0$ to $2cosx(1+sinx)=0$?
• Oct 21st 2012, 07:58 PM
chiro
Re: trig problem involving double angle forumlas
Hey kingsolomonsgrave.

They are factoring out cos(x) of both sides. Remember that in distributive law if you have ab + ac, then you can factor this out to get a(b+c).
• Oct 21st 2012, 08:04 PM
kingsolomonsgrave
Re: trig problem involving double angle forumlas
OH! of course, thanks!