posted by marie darling on .
Find all solutions for the equation 3cos(x)=cot(x).
When do I use +2kpi? Is it only when I'm suppose to "find all solutions"?
I got sin(x)=1/3. Is that correct?
3 cos x = cos x / sin x
trick is that if cos x = 0, that is a solution so
x = pi/2 or x = 3 pi/2 are solutions
as well as when sin x = 1/3
sin^-1(1/3) = 19.5 degrees or .34 radians
or 180 - 19.5 = 160.5 degrees or 2.8 radians