Very unhelpful, you fail to communicate what requires solving and instead would rather confuse those seeking assistance. This is not a tutoring service obviously but its suppose to be a "math help" forum so it totally defeats the purpose if you are unwilling to help solve the problem at hand. Why would you ask me to solve a question totally unrelated if I do not know how it connects to the end answer? That is not going to help anyone. Geez very disappointing..
Do you know how to solve cos(θ) = k?
Do you know the identity sin^2(θ) + cos^2(θ) == 1?
Can you solve quadratic equations?
These are prerequisites to solving this equation.