() r=a cos6 3. ifs be the length of the arc of the catenary y=c ccosh (r/c) from the points (0, c) to ,y) prove that =2+s2 piad the lenath of the arc of the cat

() r=a cos6 3. Ifs be the length of the arc of the catenary y=c ccosh (r/c) from the points (0, c) to ,y) prove that =2+s2 Piad the lenath of the arc of the catenary y= ccosh x/c between the point given by t0 no