Exercise 4.1
https://www.youtube.com/watch?v=yhY8Hh3hNbI&list=PL2qtWkm0Z4cf1sXqG2hiqeP7PNxJJx6kB
Exercise 4.2
https://www.youtube.com/watch?v=xgjzQYG6Qcs&list=PL2qtWkm0Z4cfAv9sN8Q-DcU6KjeyMRzgC
Exercise 4.3
https://www.youtube.com/watch?v=b0kDbw9nf7M&list=PL2qtWkm0Z4cfnf3NCvayHzJGAFl8eewLb
Exercise 4.4
https://www.youtube.com/watch?v=Hmaj8NO2c_4&list=PL2qtWkm0Z4ccAhD04_8rTIMY0qYImBz8D
Exercise 4.5
https://www.youtube.com/watch?v=p5mllVq8BHM&list=PL2qtWkm0Z4cfedmTOHeHJ7pIk87VavGgZ
Exercise 4.6
https://www.youtube.com/watch?v=iuFdlJwgGUA&list=PL2qtWkm0Z4cfFpNY9qj4MKpDf5URpct1Q
Examples
https://www.youtube.com/watch?v=F0T4DB4Tbm0&list=PL2qtWkm0Z4cfK7WMZnQ7AJ5TgRCLuW2uo
https://www.youtube.com/watch?v=yhY8Hh3hNbI&list=PL2qtWkm0Z4cf1sXqG2hiqeP7PNxJJx6kB
Exercise 4.2
https://www.youtube.com/watch?v=xgjzQYG6Qcs&list=PL2qtWkm0Z4cfAv9sN8Q-DcU6KjeyMRzgC
Exercise 4.3
https://www.youtube.com/watch?v=b0kDbw9nf7M&list=PL2qtWkm0Z4cfnf3NCvayHzJGAFl8eewLb
Exercise 4.4
https://www.youtube.com/watch?v=Hmaj8NO2c_4&list=PL2qtWkm0Z4ccAhD04_8rTIMY0qYImBz8D
Exercise 4.5
https://www.youtube.com/watch?v=p5mllVq8BHM&list=PL2qtWkm0Z4cfedmTOHeHJ7pIk87VavGgZ
Exercise 4.6
https://www.youtube.com/watch?v=iuFdlJwgGUA&list=PL2qtWkm0Z4cfFpNY9qj4MKpDf5URpct1Q
Examples
https://www.youtube.com/watch?v=F0T4DB4Tbm0&list=PL2qtWkm0Z4cfK7WMZnQ7AJ5TgRCLuW2uo