I would appreciate some help with the following question, which is, prove that:
If I do it like this:
I thought of doing it like this:
So I can't seem to do it.
I did first have to show that:
, which I was able to do.
Any help would be very much appreciated,
Thank you both for taking the time to reply.
(There's nothing in the chapter I'm working through about either of the methods you have shown me, but I will study your posts in detail to see what I can learn from them.
Thank you very much for you efforts.)
Edit: Ah, actually there is an example showing how to determine which quadrant the angle is in. I never learnt that, I'm not sure how I got by without it. It seems pretty important, in fact, looking back it's one of the first things I should have learnt in trigonometry.
(I will see if I can get:
just now seeing that is beyond me, but I guess I need to know that.)
Thank you very much indeed for your help.
Edit: I think I understand now. Since and both and is in the second quadrant, . Thanks for pointing that out. I'm glad I know that now.