Two link planar robot elbow errors in textbook (Inverse kinematics)

[Ineedhelpwithphysics]

Homework Statement

The textbook is telling me this is elbow up but when I search on the internet it shows me something else.

Relevant Equations

law of cosines, law of sines, Pythagorean theorem

Textbook: vvvvv

Online: VVVV

 

[Ineedhelpwithphysics]

Which one is right?

 

[Lnewqban]

Which one is right?

Could you explain your question a little more?
What force is animating this mechanism?

 

[hutchphd]

This is strictly a matter of how these terms are defined by the text. The angles must correspond to the definitions provided. Possibly the book screwed it up: the illustrations and text are often done by different groups of people..This is why coordinate systems should be indicated explicitly..