Answer:
12 units
Step-by-step explanation:
The lactus rectum for a parabola is equal to 4 times the length of the focus from the vertex. Therefore, we need to determine the focus 
by using the equation 
for a vertical parabola.
We can deduce that 
, 
, and 
. Therefore, the focus of the parabola is 
or 
.
Because the focus is , then it is 3 units away from the vertex 
, making the length of the latus rectum 3*4=12 units.
This is saying that four is the result of a number "x" minus 12....therefore the equation is x-12=4
Answer:
Step-by-step explanation:
![a.\\\frac{d}{dx}(\frac{-1}{1+x^2} )=\frac{d}{dx} [-1(1+x^2)^{-1}]=-1(-1)(1+x^2)^{-2}(2x)=\frac{2x}{(1+x^2)^2 }\\](https://tex.z-dn.net/?f=a.%5C%5C%5Cfrac%7Bd%7D%7Bdx%7D%28%5Cfrac%7B-1%7D%7B1%2Bx%5E2%7D%20%29%3D%5Cfrac%7Bd%7D%7Bdx%7D%20%5B-1%281%2Bx%5E2%29%5E%7B-1%7D%5D%3D-1%28-1%29%281%2Bx%5E2%29%5E%7B-2%7D%282x%29%3D%5Cfrac%7B2x%7D%7B%281%2Bx%5E2%29%5E2%20%7D%5C%5C)
b.
put 1+x²=u
2x dx=du
when x=0,u=1
when x=2,u=1+2²=5
If i understand correctly, in between lines BD and lines DC, there is marks. Both sjdes have the same marks which could mean that thwy are equal. So, 18 + 18 = 36
