Thank you for your help! I solved it now but with the method I tried at first: I had made sloppy mistakes somewhere. Since (thanks to flora) cos(A + B) = cosAcosB - sinAsinB I got (sinA + cosAtanB)/(cosA - sinAtanB) and, calculating cosA through (1 - sinAsinA)^½ I get that sinA + cosAtanB = cosA...
cos(A + B) = cos(A)cos(B) + sin(A)sin(B). At least I believe it is so.
Your message was unfortunately not beneficial for me as I find your triangle hint rather vague.
Hello, I have been trying to solve this type of question but the results of my efforts are frequently disappointing. Since this is considered elementary and simple I have no doubt that someone can help me with this:
Solve arcsin (3/5) + arctan (1/7).
What if it had said 641/19 instead of...
mathwonk: yes I do in fact have problems with my general negative outlook on things. I don't know where that has come from but it so often leads to the truth that it is tempting to state that pessimism equals realism, with little or no exceptions. So, yeah, that is probably why I describe myself...
Halls of Ivy: No I do not know anything about the mathematical community (apologize for that being unclear. I tried to with saying I was new and all) - that is one of the reasons why I asked about it in the first place; the very little of it I had read and seen had given me a (an apparently)...
Prologue:
Hello, I am new to this forum. This is my first post. I come from Sweden, discovered an interest in mathematics when I was fourteen, pursued it in fluctuating vigour for two years until I dropped it completely for a whole three (personal reasons).
Now I'm nineteen, and just a few...