Vertical inclination from pitch and roll

Question

I am a bit confused on how to compute the angle between R and the $z$-axis, knowing the roll($Ayz$) and the pitch($Axz$). We know also the length of R. Can someone help me please?

The schematic can be found here: https://i1.wp.com/ozzmaker.com/wp-content/uploads/2013/04/logo2.png?resize=767%2C576

Thank you for your help!

Answer 1

finally found out:

We have to do a tangent on both roll and pitch, apply the Pythagorean theorem, and then arctan

inclination = atan(sqrt(tan^2(roll)+tan^2(pitch)))