Write utility function for perfect substitute, Perfect complement, Quasilinear and cobb Douglas utility function and draw their corresponding Indifference curve? b) What is marginal utility and marginal rate of substitution? Show mathematically? c) What kind of preferences are represented by a utility function of the form u(x₁x₂) = x₁ + √x₂? Is the utility function v(x₁x₂) = x₁² + 2x₁√√x₂ + x2 a monotonic transformation of u (X1, X2)?