show that the second fundamental coefficients transform as follows:\

L=L^(**)\\\\theta _(u)^(2)+2M^(**)\\\\theta _(u)\\\\phi _(u)+M^(**)\\\\phi _(u)^(2)\ M=L^(**)\\\\theta _(u)\\\\theta _(v)+M^(**)(\\\\theta _(u)\\\\phi _(v)+\\\\phi _(u)\\\\theta _(v))+N^(**)\\\\phi _(u)\\\\phi _(v)\ N=L^(**)\\\\theta _(v)^(2)+2M^(**)\\\\theta _(v)\\\\phi _(v)+N^(**)\\\\phi _(v)^(2)

\ 9.44. Show that the Gauss and mean curvatures on

x=(u+v)e_(1)+(u-v)e_(2)+uve_(3)

at

u=1,v=1

are

K=(1)/(16)

and

H=(1)/(8)\\\\sqrt(2)

.

L=Lu2+2Muu+Mu2M=Luv+M(uv+uv)+NuvN=Lv2+2Mvv+Nv2 Show that the Gauss and mean curvatures on x=(u+v)e1+(uv)e2+uve3 at u=1,v=1 are K=1/16 and H=1/82