Answer:
Answered
Explanation:
function from S_1 to S_2 (functions have unique mapping
each element in S_1 has 2 elements to map to in S_2 and there are 3 elements in S_1
therefore number of functions = 2^3 = 8 (2 choices for each of 3 elements)
a) relations between S_1 and S_2 are subset of S_1 x S_2
there are 6 elements in S_1 x S_2 therefore relations would be 2^6 = 64
(no of subsets of set of n elements = 2^n)
b) By above explanation functions from S_2 to S_1 = 3^2 = 9
and relation from S_2 to S_2 = 2^4 = 16
Answer:
Electronic mail is a method of exchanging messages between people using electronic devices. Email entered limited use in the 1960s, but users could only send to users of the same computer, and some early email systems required the author and the recipient to both be online simultaneously, similar to instant messaging.
That would be what is known as Spyware, a common form of this is known as a "Trojan Horse". This type of malware is typically latched on and hidden within files, such as when downloading a pirated version of a song, game, art-work, etc...
Answer:
host-based security measures
Explanation:
Anti-virus, host-based firewall, system hardening, change control, and log management are host based.
