Consider the surface S consisting of the portion of the graph of the function z = x? + y above the annulus 4

Extracted text: Consider the surface S consisting of the portion of the graph of the function z = x? + y above the annulus 4<9. 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)="(O,I" i)="" y="" vz).="" +y?="" b)="" consider="" the="" vector="" field="" f="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="">