Advantages & disadvantages of DDA:-

• Faster than the direct use of the line equation and it does not do any floating point multiplication.
• Floating point Addition is still needed.
• Precision loss because of rounding off.
• Pixels drift farther apart if line is relatively larger.

Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent. For example, changes in the signal strength can be used to reflect the sounds to be reproduced by a speaker, or to specify the light intensity of television pixels.

There are some disadvantages of the Waterfall Model.
1) As it is very important to gather all possible requirements during the Requirement Gathering and Analysis phase in order to properly design the system, not all requirements are received at once, the requirements from customer goes on getting added to the list even after the end of "Requirement Gathering and Analysis" phase, this affects the system development process and its success in negative aspects.