ocr: 7. - a) Suppose u=f(xtat, y+bt) with a,b constant. au Show that at = a - ax Bu + b ay du b) Find the linear approximation of f(x,y) = ex arctan(y) at (1,1).- c) Evaluate pe-xldx. -0 8. a) Use Green's theorem to evaluate xtan'ydy + en cosy dx C where C is the triangle with vertices (0,0) (7.0) - 47. b) Find the point of intersection of the lines Ll: x=2t-1, y-3t+1, z= -4t+2 and L2: x=S+4, y= -4s+3, Z=S-5.
