The subject matter of this book has been presented in this book has complete theory and large number of solved examples. We have been sufficient problems from various Universities examination papers. I have spared no pains in applying my long experience of degree class teaching to make the book useful to the students. We have tried to our best to keep the book free from the misprint. The author shall be grateful to the readers who point out errors and omissions which inspite of all care might have been there.