suppose I have an equations of the following with two unknowns $A$ and $\theta$
I have two points $(E,F) (G,H)$ how do I go about solving this equation analytically. I can solve this equation by using least squares where I just plugin a few numbers and solve it iteratively.
I was thinking about using trig identities and breaking it down to $A\sin(x)\cos(\theta)+Acos(x)\sin(\theta)=D$
But I am kind of stuck at that point. Using derivative to solve the equation doesn't help since the form of the equation is still $\cos(x+\theta)$