This is a live document. Updates will be announced in the Messages section. Supplementary documents may be posted. === 01 === wk. 36 * All problems are taken from the exam problem collection, except the last which is just quoted below: * You will need: - recall the definition of inflection point, which is where f'' changes sign. - the 'range' ('verdimengden') of a function f = those values that f attains when x runs through the entire domain of definition Notice that 'sketch' a graph means 'sketch' -- get the qualitative properties visible, not get it pretty. Don't spend too much time on this. * Problems: - From the compendium: 15, 18, 32 except part (c), 115, 117. - Let F(x,y) = x exp(y) be a production function defined for nonnegative x,y. Consider a level curve F(x,y)=C, C>0, on which y is a function of x. Then y can be solved explicitely as y= ln C - ln x, but in problems (a)--(c) you are asked to NOT solve this way, but use the implicit calculations rules: (a) Compute the MRS = - dy/dx on this level curve using implicit differentiation. (b) Compute the elasticity of y wrt. x (c) Compute the elasticity of substitution of F by using the fomula in the book (d) Verify your answers in (a)--(c) by calculating in a different manner (in (a), (b) use the form y = ln C - ln x, while in (c) calculate the ratio d ln (y/x) / d ln MRS. === 02 === wk. 37 === From the compendium: problems 43 44 53 (c) 54 110 (a) === 03 === wk. 38 === Problem 30 from the compendium. Then, replace the equality sign in the constraint by ¡Ü (less-than-or-equal), consider merely the maximization problem, and use your calculations from the Lagrange problem to check which points satisfy the Kuhn--Tucker conditions. Problem 132 from the compendium Exam autumn 2007 problem 2 Exam autumn 2007 problem 4 Exam autumn 2009 problem 2 === 04 === wk. 39 === Some of these problems involve integrals that are not easy without practice; you could try a few easier ones from the book first. And if you are still stuck, try again after Monday's lecture. All problems from the compendium: Problem 28 (this is a long one, from the era of full-day exams. Don't worry if you find it hard.) Problem 21 (a) Problem 49 Problem 100 (a), (b) -- for the latter there are many choices where you would have to substitute again. Problem 109 (a) Problem 110 === 05 === wk. 40 === All from the collection: 88 94 100 120 -> this is solvable both as a separable and as a linear differential equation. Do both (the latter requires Monday's lecture). 127 -> solve part (a) in two different ways. 134 -> part (a) requires Monday's lecture. And if this joke helps you remember the constant, then it's worth it: - What is the indefinite integral of 1/cabin wrt. cabin? - ... a log cabin? - No, a houseboat. You forgot the C. === No teaching wk 41 === 06 === wk. 42 === Problem 53 (a) and (b) Problem 65 (a) Problem 71 Problem 84 Problem 109 Exam spring 2009 # 4