Step-by-step explanation:
Given that,
a)
X ~ Bernoulli
and Y ~ Bernoulli 
X + Y = Z
The possible value for Z are Z = 0 when X = 0 and Y = 0
and Z = 1 when X = 0 and Y = 1 or when X = 1 and Y = 0
If X and Y can not be both equal to 1 , then the probability mass function of the random variable Z takes on the value of 0 for any value of Z other than 0 and 1,
Therefore Z is a Bernoulli random variable
b)
If X and Y can not be both equal to 1
then,
or 
and 

c)
If both X = 1 and Y = 1 then Z = 2
The possible values of the random variable Z are 0, 1 and 2.
since a Bernoulli variable should be take on only values 0 and 1 the random variable Z does not have Bernoulli distribution
From trigonometry we know that:
if 
then,
(where
is an integer)
This can be rewritten in degrees as:
.............(Equation 1)
Now, in our case, 
Therefore, (Equation 1) can be written as:
..........(Equation 2)
Now, to find the correct options all that we have to do is replace n by relevant integers and find the values of
that match.
For n=2, (Equation 2) gives us:
.
Thus, 
Now, we know that: 
Let n=-1, then:

Thus, 
Likewise, 
Only the last option
will never match
because no integral value of
will ever give 
Thus the last option is the correct option.
Answer: A) 45 ft
Step-by-step
The yardstick is 3ft tall since 1 yard = 3ft. It is 3 times as tall as its shadow. The tree has a 15ft long shadow. The tree should also be 3 times as tall as its shadow. The tree is 15*3ft tall, so it is 45ft tall. I attached an image of the diagram I made.
Answer:
NO WAY ITS INSANE
Step-by-step explanation: