If ##g(x)=1/2x^2+3##, what is ##g(-4)##?

##g(-4) = 11##

To calculate ##g(-4)## you must substitute ##-4## for ##x## and then do the necessary arithmetic:

##g(-4) = 1/2(-4^2) + 3##

##g(-4) = 1/2 xx 16 + 3##

##g(-4) = 8 + 3##

##g(-4) = 11##