Let F? =(9a2x+10ay2)i? +(10z3?6ay)j? ?(3z+10x2+10y2)k? .
(a) Find the value(s) of a making div F? =0
a=
(Enter your value, or if you have more than one, enter a comma-separated list of your values.)
(b) Find the value(s) of a making div F? a minimum
a=