I have a problem, I'm trying to solve inverse kinematics problem, but I have hit the wall. I have 2 equation for $$\cos(\theta_2) \cos(\theta_3) - \sin(\theta_2) \sin(\theta_3) = 45.7518$$ and for $$\sin(\theta_3) \cos(\theta_2) + \sin (\theta_2) \cos(\theta_3) = -32.7842$$
I know that $\theta_2 + \theta_3 = -35.5$, $\theta_2 = 30$ and $\theta_3=-65.5$ Unfortunately I have no idea how can I solve it to get those answers. It probably has something to do with trigonometry. I hope someone will help me. And I don't even know if I have given enough information to solve it.
All value here are in degrees.
I have another question - let's say for a moment that this $45.7518$ is the answer to first equation, now if I call a function $acos(45.7518)$ I will get the $\theta_2 + \theta_3$? And also $asin(-32.7842)$ to get value of $\theta_2 + \theta_3$?