Curvature radius of fixed beam

Hi!!

I was reading some theory in the "Beer & Jhonston - Mechanics of materials" book and I found this part thas is causing me troubles...

Cantilever1.jpg Cantilever2.jpg


It says that at the free side of the beam, the radius of curvature is "infinite" and that, at the fixed side of the beam it is almost cero. I understand the mathematics, when you divide by 0 at point A (x = 0) it becomes "infinite" but, I don´t understand the geometry of what its happening... why ... at the point where the beam has the maximum deformation, the radius of curvature (rho) is maximum ... and when the you analize the fixed side (B) it is smaller (almost cero)...

I understand that a big curvature radius, implies a small deformation and a small curvature radius implies a big deformation as in the next picture:

WhatsApp Image 2018-02-14 at 3.15.31 PM.jpeg

Can someone help me to understand?