Instructor:Quanlei FangDept. of Math, University at Buffalo, Spring 2009WelcometoMath 122 Lecture 6Survey of Calculus and its Applications I1Partial derivativesLast timeLast timeDefinitionExamplePartial Derivative of f(x,y)with respect to x: written,the derivative off(x,y),whereyis treated as aconstant andf(x,y) isconsidered as a function ofxaloneIf, thenxf∂∂()432,yxyxf=.8and63342yxyfyxxf=∂∂=∂∂
Maxima and Minima of FunctionsMaxima and Minima of Functionsof Several Variablesof Several Variables§7.3Relative Maxima and MinimaFirst Derivative Test for Functions of Two VariablesSecond Derivative Test for Functions of TwoVariablesFinding Relative Maxima and MinimaRelative Maxima & MinimaRelative Maxima & MinimaDefinitionExampleRelative Maximum of f(x,y):f(x,y) has a relativemaximum whenx=a,y=biff(x,y) is at most equal tof(a,b) wheneverxis nearaandyis is nearb.