a.
is a joint density function if its integral over the given support is 1:


so the answer is yes.
b. We should first find the density of the marginal distribution,
:


Then

or about 0.2019.
For the other probability, we can use the joint PDF directly:

which is about 0.7326.
c. We already know the PDF for
, so we just integrate:
![E[Y]=\displaystyle\int_{-\infty}^\infty y\,f_Y(y)\,\mathrm dy=\frac15\int_0^\infty ye^{-y/5}\,\mathrm dy=\boxed5](https://tex.z-dn.net/?f=E%5BY%5D%3D%5Cdisplaystyle%5Cint_%7B-%5Cinfty%7D%5E%5Cinfty%20y%5C%2Cf_Y%28y%29%5C%2C%5Cmathrm%20dy%3D%5Cfrac15%5Cint_0%5E%5Cinfty%20ye%5E%7B-y%2F5%7D%5C%2C%5Cmathrm%20dy%3D%5Cboxed5)
The answer is (20,0). We can determine the sum of two vector points by adding x1 to x2 and y1 to y2. This is like adding integers, the only difference is the answer is in vector form. In here, we have (x,y). x = 7+13 and y = 5+(-5). that is why we have the (20,0) as the answer.
Answer:
Below.
Step-by-step explanation:
f(x) = |x| This is shaped like a V with the vertex at (0,0).
f(x) = |x| + 3 this is also shaped live a V with the vertex at (0, 3).
(This is |x| translated up 3 units).
f(x) = |x| - 6 similar to the above with the vertex at (0, -6).
(This is |x| translated down 6 units).
Hey There!
First you would need to factor out the two.
-4x^3/2 = -2x^3
2x^2/2= x^2
12x/2= 6x
6/2= 3
Now we have.
-2x^3+x^2+6x+3 / x+1
We would then factor with polynomial division, and then we should have.
-2(2x^2 - 3x - 3)(x+1) / x+1
We would then cancel out the x+1
Therefore, the answer would be 
Hope this helped!
Answer:
30 degrees
Step-by-step explanation:
tanA=4√3/12
A=30