a)Determine where the lineL :x= (-1, 8, 9)+t(3,-9,-4)and the plane

E:-2x1+6x2+3x3+19=0intersect and calculate the angle between

them.

b)Given the two planes

E:.=2.x+3x2+7x3+2=0, E’ : x=(3,0,0)+ s(-2,0,0)+t(3,0,1)

find the line of intersection and the angle between them.