i have a huge problem when it comes to finding the second angle of an equation like this for eg cos(x-73.4)=3/5 
the first angle is easy to find but i really need help to find the second angle, can anyone give me a step by step solution?
thanks alot!!!
masterof13
well at first you obviously have to cos
-1 3/5, so you get an angle right?
since this is cosine and +ve, you also do 360 - the angle
remember, CAST
in the first quadrant, sin cosine and tan are all +ve.
in teh second quadrant, sin only is +ve. (you do 180 - the angle)
in the third quadrant, tan only is +ve. (180 + the angle)
in the fourth quadrant, cos only is +ve. (360 - the angle)
so if you get a +ve angle with sin for example, your answer would be that angle, and 180 - the angle.
if you get a +ve angle with tan, your answer would be that angle, and 180 + the angle.
also, any angle + 360 is the same angle, but usually you don't have to do that because it's not in the range.
i hope this helps. feel free to ask me if you still have any questions.
