(a) Given a closed region containing a multitude of point charges has the expression for the electric flux density as D=8x 3 y 2 za x ​ +5x 2 y 5 a y ​ +6xyza z ​ C/m 2 , calculate the volume charge density at the point P 1 ​ (1,2,5). (b) Given the expression of the potential field in a closed region is V=18x 3 y 2 z−5y 3 z 2 V. calculate the potential V and the electric field intensity E at point P s ​ (2,3,0).