📋 Formulario

Complete Theory

Worked Examples

Example 1Gradient and tangent plane
Example 2A limit that does not exist
Example 3Critical points
Example 4Implicit function (Dini)
Example 5Constrained optimisation (Lagrange)

Exercises with Solutions

Exercise 1GradientMedium
📋 Problem to solve
Compute f(1,1)\nabla f(1,-1) for f=xey+y2f=xe^y+y^2.
Exercise 2Directional derivativeMedium
📋 Problem to solve
Derivative of f=x2+y2f=x^2+y^2 at (1,1)(1,1) along v^=(1,0)\hat v=(1,0).
Exercise 3LimitsHard
📋 Problem to solve
Decide whether lim(x,y)(0,0)x2yx4+y2\lim_{(x,y)\to(0,0)}\dfrac{x^2y}{x^4+y^2} exists.
Exercise 4TaylorMedium
📋 Problem to solve
Second-order Taylor of ex+ye^{x+y} at (0,0)(0,0).
Exercise 5Implicit functionHard
📋 Problem to solve
For x2+y2+z2=1x^2+y^2+z^2=1 find z/x\partial z/\partial x at (1/3,1/3,1/3)(1/\sqrt3,1/\sqrt3,1/\sqrt3).
Exercise 6LagrangeHard
📋 Problem to solve
Minimise f=x2+y2f=x^2+y^2 on the constraint x+2y=5x+2y=5.