you need to memorise this for extension 1
		
		
	 
1. I don't do extension 1
And 2. I have memorised it which is why I can use my formula and not theirs
I know I'm feeding the ragebait here but
If you actually read the context and posts immediately following that, you'd know that,
Imo, once you know ASTC, and know the formulas for quads 1,2,3,4 THEN you can use my ones, because they rely on YOU to match the quadrant to the +/- and formula. 
What I'm actually saying is, they shouldn't use their formula's in the questions later on, as it is misleading and adds extra steps. What I'm suggesting is eliminating the algebra so you can skip straight to the step where you do the working out. I.e instead of 180+theta it's actually x-180, since thats what you have to do anyway 

Thanks for coming to my Ted talk