Score Applicable Major. Civil Engineering I: Fill blanks (5 items, 3 points per blank, a total of 15 points) 1. The order of differential equation 3y -y-y' =0 is 2. The equation of the plane with the normal vector n = (1,2,3) and the point (2,3,1) is 3. If f(x, y) = 3xy-xy. f(x,p) =_f,(x,y )=_ 4. a and b are two vectors, o is the angle between a and b , a-b= 5. Function f(x,y) = 2x* +5p2 attains a minimum at the pointII: Determine whether the statement is true or false. If it is false, explain why or give an example that disproves the statement. (3 points per blank, a total of 15 points. ) Score 1. The graph y= x in three-dimensional space is a straight line. ( 2. Ifaxb =0, thena, b are parallel. ( ) 3. lim sin(xy) -=0. ( ) X 4. If f(x, y) 20, [[f (x, >) dxdy represents the volume of the cylinder with a curved top. Region D is the base of the cylinder. ( ) 5. A point (x,, ).), which satisfies f, (x, y,) =0, f, (x, y.) =0, is called a stationary point of f(x, y). ( )