3. Consider the vector field y(i)=e' sin yi +e' cosyj+z+k+1(i xr), = xi + yj + zk. (i) Find 2 if the vector field is potential. Find the potential function. For this value of a calculate the line integral Jl Jdi by 2 methods (potential theory, definition of the integral), if y is the straight segment Y connecting the points A(0,0,0) and B 0, ,3 15%. (ii) For 1=1 find the value of the line integral f()dr by 2 different methods, if the closed curve is y : x = 0, y = cos 2t, z = sin 2t ,0 st st. 10+5=15% (iii) For 1 = 2 find the value of the surface integral ff (F)d by 2 different methods, if the closed surface is the boundary of the domain V: Vx + y2