Because to prevent MITD (Man in the middle is a man that in the middle of the network. For example: You are sending a text, the man in the middle or in the modem will receive the text and can edit it and send it to the receiver, or the man will put the virus in...) and to prevent server snooping
Let P(n) be "a postage of n cents can be formed using 5-cent and 17-cent stamps if n is greater than 63".Basis step: P(64) is true since 64 cents postage can be formed with one 5-cent and one 17-cent stamp.Inductive step: Assume that P(n) is true, that is, postage of n cents can be formed using 5-cent and 17-cent stamps. We will show how to form postage of n + 1 cents. By the inductive hypothesis postage of n cents can be formed using 5-cent and 17-cent stamps. If this included a 17-cent stamp, replace this 17-cent stamp with two 5-cent stamps to obtain n + 1 cents postage. Otherwise, only 5-cent stamps were used and n 65. Hence there are at least three 5-cent stamps forming n cents. Remove three of these 5-cent stamps and replace them with two 17-cent stamps to obtain n + 1 cents postage.Hence P(n + 1) is true.
The triangle indicates that the clock signal is an edge-triggered signal.
The circle indicates that the signal is low-active (ie., inverted).
The 74LS74 has a positive-edge trigger clock (low to high).
All of the above A, look up Info, B, get pictures and print, C, webpage is on the internet or computer hope this helps ~Vanessa
