Integration by parts is one of the basic methods of integration. Integration by parts, integration by substitution, and their combination provide powerful techniques of integration. Integration by parts is applicable when the integrand is a product of two functions, at least one of which is integrable and the other differentiable. There are some exceptions, for example if the integrand is , it may be written as product of two functions by writing . Similar comment applies to inverse trig functions too. Integration by parts may have to be applied more than once in some cases, for example, when an integrand is of the form etc. Purpose of this applet is to facilitate practice on method of integration by parts. Follow the instructions that may be viewed by checking the Instructions check box.