[填空题]
A right cylinder has heigh98wc-j 778jlp admwf t6xs8w r(hdu 31yim9ma t hh mm and diamj6eb 0x)s *x1ob3i*:n2 zk lpckuooe4eter xx mm. The volume of this cylinder isbxcp il)1s 0onebj *u:ko23x6z e*o4k equal to $45mm^3$.
The total surface area, A, of the cylinder can be expressed as $A = \frac{\pi}{2}x^2 + \frac{k}{x}$.
1.Find the value of k.k=
2.Find the value of x that makes the total surface area a minimum.x= mm
