Suppose that you can only use the set of small letters characters (a-z) and odd numbers (1, 3, 5, 7, 9) to set a password. What
1 answer:
Answer:
Step-by-step explanation:
To create a password, you need to select 8 characters (not necessarily different) from the set {1,3,5,7,9,a,b,c,...,z}. Now, this set has 31 elements: the 26 lowercase letters from the alphabet and the 5 odd numbers (1,3,5,7,9).
Now, there are 31 ways to choose the first character, it can be any element from our set. The second character can also be chosen in 31 ways, because there are not restrictions (repetitions, specific characters, etc). Similarly, the third, fourth, fifth, sixth, seventh and eighth characters have 31 possibilities each one.
The number of passwords is the number of ways of selecting the 8 characters, then by the multiplication principle the number of passwords is 31×31×31×31×31×31×31×31=31^8.
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Given:
To find:
The obtuse angle between the given pair of straight lines.
Solution:
The slope intercept form of a line is
...(i)
where, m is slope and b is y-intercept.
The given equations are
On comparing these equations with (i), we get
Angle between two lines whose slopes are is
Putting and
, we get
Now,
and
and
and
, so it is an obtuse angle and
, so it is an acute angle.
Therefore, the obtuse angle between the given pair of straight lines is 120°.