Consider the surface S consisting of the portion of the graph of the function z = x2 + y? above the annulus 64

Extracted text: Consider the surface S consisting of the portion of the graph of the function z = x2 + y? above the annulus 64 <81. choose="" the="" normal="" vector="" n="" to="" the="" surface="" which="" has="" positive="" third="" component.="" a)="" give="" a="" parametrization="" of="" s="" in="" terms="" of="" the="" variables="" r,0="" from="" cylindrical="" coordinates="" r(r,0)="(]," ii)="" %3d="" y="" vz).="" y2="" b)="" consider="" the="" vector="" field="" f="(-" vx?="" +y?="" +="" write="" a="" double="" integral="" in="" terms="" of="" r,0="" which="" computes="" the="" flux="" of="" f="" across="" s:="" 02="" r2="" flux="dr" de="" 01="" r1="" 01="02" =="" r1="">