UILIS questi a) For the function f(x, y) = 23 + 4x2y -2y2, write down Vf and V2 f. [2] b) Find the equation of the plane passing through the points (1,2,3), (1,-1,0) and (2,1,-1). [2] c Find an expression for cot(20) in terms of cot(0), given that cot 0 = cos(8) sin(0) 3. [2] d) Find the particular solution of the following first order ODE: dy - y = 2te2t dt The boundary condition is that y = 1 at t = 0. [3]